How to Install a ROM on an Android Device

2024 Author: Samantha Chapman | [email protected]. Last modified: 2023-12-17 09:13

This article describes how to install a custom ROM on your Android device, changing the look and functionality of your phone, giving it new life. This is an advanced procedure and it risks making the device unusable.

Steps

Part 1 of 4: Unlock the Bootloader

Step 1. Check if your device manufacturer allows unlocking the bootloader

Depending on your Android model, it may be possible to unlock the bootloader with the help of the manufacturer. Not all manufacturers allow it and even when they do, it doesn't apply to all models.

To quickly find out if your model falls into this category, search for "bootloader unlock manufacturer" (eg "Samsung bootloader unlock"). This should make the manufacturer's bootloader website appear among the first results.
Nexus phones can always be unlocked.

Step 2. Check if your carrier allows unlocking the bootloader

Even if your device manufacturer allows unlocking, it may be your carrier who prevents it.

Step 3. Understand the risks and limitations

When you unlock the bootloader, you usually void the warranty. You also interfere with your device's DRM and this can cause problems with music streaming services. Furthermore, this procedure also causes Apple Pay to be deactivated as a security measure and there is a possibility that the phone will become permanently inoperable.

Step 4. Download the Android SDK tools you will need

You need some computer programs if you want to unlock the bootloader.

Visit the Android developer website.
Scroll down to the "Get Command Line Tools Only" section at the bottom of the page.
Click the link for the ZIP archive compatible with your operating system.
Put the ZIP file in the folder where you will save the tools.

Step 5. Extract the ZIP archive

Double click on the file after placing it in the desired folder, then click the "Extract" item.

Step 6. Run Android SDK Manager

The list of available SDK tools will open.

Step 7. Uncheck all boxes except Android SDK Platform-tools

This is the only program you need to unlock the bootloader.

Step 8. Click Install

Step 9. Download and install the USB drivers for your device

You will find them on the support page of your phone manufacturer's website. Make sure you download the drivers compatible with your model.

Step 10. Connect the Android device to the computer via USB

Step 11. Open the platform-tools folder inside the path where the SDK tools are located

The directory was created when you installed the program.

Step 12. Hold Shift and right click on the folder

Make sure you do this in an empty spot.

Step 13. Click Open Command Prompt Window Here

A command prompt window will open that is already set to the correct path.

Step 14. Type adb devices, then hit Enter

You should see the serial number of your device.

Step 15. Open the Settings of your Android device

Step 16. Scroll down and press About phone

Step 17. Press the Build Number button seven times

This enables the Developer Options menu.

Step 18. Go back to Settings and hit Developer Options

Step 19. Enable OEM Unlock (if present)

You won't find this entry on all phones and you only need to enable it if it's available.

Step 20. Enable USB Debugging

This allows you to send commands to your Android device via ADB.

Step 21. Open the device manufacturer's unlock procedure instructions

The operation varies according to the manufacturer. Make sure you follow the directions provided to the letter. The following is a general guide.

Step 22. Reboot your device in fastboot mode

The steps to do this vary by phone, but you'll usually need to turn it off, then hold the Power and Volume Down buttons for 10 seconds.

Step 23. Enter the unlock key recovery command on ADB

The command is different for each manufacturer. For example, for HTC mobiles you should write fastboot oem get_identifier_token.

Make sure your Android device is still connected to your computer and that the Command Prompt window is open and on the path to the platform-tools program folder

Step 24. Copy the device identification code

You will see a long code appear on the screen, which can be divided by several dashes. Click and drag to select it all. Press Ctrl + C to copy it.

Step 25. Send the device code to the manufacturer

To do this, use the bootloader unlock request form and request the unlock code. It can take a week or two for the request to be processed, depending on the manufacturer.

Step 26. Run the command specified by the manufacturer

When you receive an unlock code, you get a command that you can use to apply it to your device, different for each manufacturer. The Android device must be connected to the computer and in fastboot mode.

For Nexus devices, run fastboot oem unlock or fastboot flashing unlock for Nexus 5X and newer models.
The command required by your device manufacturer may be different. For example, users with an HTC need to write fastboot oem unlocktoken Unlock_code.bin once the Unlock_code.bin file received from the manufacturer has been placed in the ADB folder.

Step 27. Confirm unlocking

The phone may ask you to confirm the operation.

Step 28. Write fastboot reboot on your computer

With this command the device will restart and exit fastboot mode.

Step 29. Look for the Bootloader Unlocked message

You will see this every time you turn on the device, as a safety measure. Make sure the Android OS starts normally. You are now ready to install a custom recovery.

Step 30. Find and follow a specific guide for your model if you are unable to unlock the bootloader

If your device manufacturer or operator does not allow this, the only solution is to find an exploit that can bypass the restriction. The process is different for all phones and some simply cannot be unlocked.

The first place you should look is the XDA forum. Find your phone model and search for community-published unlocking methods.
When unlocking with an exploit, make sure you follow all the steps on the forum to the letter, because the risk of breaking your phone permanently is much higher if you don't use an official method.

Part 2 of 4: Install a Custom Recovery

Step 1. Visit the TWRP website

This guide explains how to install TeamWinRecoveryProject (TWRP), one of the most used recovery methods for Android ROMs. Another popular software is ClockworkMod Recovery (CWM). With both you should be able to install almost any ROM, although some require a specific recovery environment.

Step 2. Click the Devices tab

Step 3. Check if your device is supported

If it's not on this page, try an alternative recovery environment, such as CWM.

Note that your carrier or region may not be supported even if the device is on the list

Step 4. Click the link for your device

This will allow you to view more details for the specific model.

Step 5. Click the Download button

You will download to your computer TWRP in IMG format.

Step 6. Copy the IMG file to your ADB folder

Put it in the same location as the ADB execution files. This way you can transfer it to your phone using ADB with command prompt.

Step 7. Rename the file to twrp.img

This will make it easier to enter the name during the transfer.

Step 8. Type adb reboot bootloader in the command prompt

If you haven't opened Command Prompt yet, hold down Shift, then right-click on the platform-tools folder. Select "Open Command Prompt Window Here".

Step 9. Type fastboot flash recovery twrp.img, then press Enter

Doing this will copy the TWRP image file to the Android device and replace the current recovery environment with it.

Step 10. Type fastboot reboot, then press Enter

Step 11. Press and hold the Volume Up and Power buttons while the device restarts

This procedure opens recovery mode for almost all phones.

Some devices require a different key combination to enter recovery mode. Search the internet for "(your phone model) recovery mode"

Step 12. Enter your PIN if asked

This allows TWRP to access the encrypted data of the device and is very important to create a backup.

Step 13. Press Backup

TWRP Backup Utility will open. By creating a full system backup (NANDroid) you will have the option to restore your device if something goes wrong during the ROM installation.

Step 14. Select Boot, System and Data

With this operation, you back up all system files and essential data.

Step 15. Slide the bar to start the backup

You will see it at the bottom of the screen. It will probably take a few minutes to complete, so let your Android device work.

Step 16. Go back to the Backup menu and delete all options

Step 17. Scroll to the bottom of the page and select your special partition after Recovery

The name will differ by device (PDS, EFS, WiMAX, etc.) and in some cases you won't find any entries.

Step 18. Start backup special partition after selecting it

This way you create a copy of the IMEI information, which is essential for restoring connectivity if something goes wrong later on.

Part 3 of 4: Finding a ROM

Step 1. Visit the XDA forum

This is the best known Android development community on the internet, where you can find almost any ROM available.

Step 2. Open the subsection of your device

The pages dedicated to the most used phones are listed on the main page, otherwise you can use the search bar to find your specific model.

When choosing the model make sure that the operator is also the right one. The same devices from two different carriers have different model numbers and you need a specific ROM for your phone

Step 3. Scroll to the ROMS, KERNELS, RECOVERIES, & OTHER DEVELOPMENT section

On the XDA forums, each device has a section dedicated to ROM development. On these pages you will find almost all the ROMs available for your model.

Step 4. Find a ROM that interests you

The number of ROMs available for your device varies a lot based on its popularity. For some you will find only one or two, while for others dozens. In extreme cases you will not find any ROMs, but these are usually the models whose bootloader cannot be unlocked.

The various ROMs have different functionalities. Some are designed as simply as possible to maximize performance, while others add tons of options not normally available

Step 5. Consider features and limitations

ROMs often add new features, but they can also have limitations that weren't present in the original device. Make sure that the ROM you have chosen fully satisfies you.

Step 6. Read carefully the entire post dedicated to the ROM

Many ROMs need to be installed following special instructions. It is very important to follow the author's directions to the letter or you may run into serious problems.

Step 7. Click the Download ROM file button

This will start downloading the ROM, usually in ZIP format. They can be quite large, so downloading can take a few minutes.

Step 8. Visit the GApps download site

Here you can download Google-owned apps, such as Gmail and the Play Store, as they cannot be included in ROMs for legal reasons.

Step 9. Select your device configuration on the GApps website

You must indicate the architecture (platform), the version of the operating system and the desired variant.

If you don't know the platform of your device, you can find this information on the page dedicated to that model on the XDA forums.
Make sure the OS version is the same as the ROM you want to install, not the current one.
In most cases, you can choose Stock, which includes all the default Google apps.

Step 10. Click the Download button

This will start downloading the GApps package you have selected. You should now see two ZIP files: the ROM you have chosen and the GApps file.

Part 4 of 4: Install the ROM

Step 1. Connect the Android device to your computer

If you haven't done so already, you need to connect it via USB to your computer, so you can transfer the files to your phone's memory.

Step 2. Open the Android device folder on your computer

You can transfer files to the phone's internal memory, or to the SD card if you have one inserted.

Step 3. Copy the Gapps ROM and ZIP file to your Android device

You can drag them to the phone folder. Make sure you put them in the root folder of your internal storage or SD card (don't put them in subfolders).

Step 4. Unplug your phone after the transfer is complete

Step 5. Turn off the Android device

You have to open the Recovery mode and you can do it starting from the phone off.

Step 6. Boot your device into recovery mode

The procedure for doing this varies by model, so do an internet search if you don't know it. Generally, you will need to hold down the Power and Volume Down buttons until the recovery menu appears. You will know you are on the right screen if you see TWRP.