Basic requirements

  1. Make sure your computer has working adb. Setup instructions can be found here.
  2. Enable USB debugging on your device.

Unlocking the bootloader

  1. Enable OEM unlock in the Developer options settings on the device, if present.

  2. Connect the device to your PC via USB.
  3. Open a terminal on the PC and boot the device to fastboot mode by typing:

     adb reboot bootloader
    

    You can also boot into fastboot mode via a key combination:

    • With the device powered down, hold the Volume Down and Power buttons until HBOOT appears, then release the buttons.
  4. Once the device is in fastboot mode, verify your PC finds it by typing:

     fastboot devices
    

    If you see no permissions fastboot or <waiting for device>, try running fastboot as root/Administrator.

  5. From the same terminal, type the following command to obtain your bootloader unlock token:

     fastboot oem get_identifier_token
    
  6. Visit the HTCDev Bootloader Unlock website and follow the instructions there to obtain your unlock key and unlock your bootloader. If your device does not appear in the drop-down list, select All Other Supported Models.

  7. If the device doesn’t automatically reboot, reboot it. It should now be unlocked.
  8. Since the device resets completely, you will need to re-enable USB debugging to continue.

Installing a custom recovery using fastboot

  1. Download recovery - visit twrp.me to obtain the latest version of Team Win Recovery Project for your device.
  2. Connect your device to your PC via USB.
  3. Open a terminal on the PC and boot the device to fastboot mode by typing:

     adb reboot bootloader
    

    You can also boot into fastboot mode via a key combination:

    • With the device powered down, hold the Volume Down and Power buttons until HBOOT appears, then release the buttons.
  4. Once the device is in fastboot mode, verify your PC finds it by typing:

     fastboot devices
    

    If you see no permissions fastboot or <waiting for device>, try running fastboot as root/Administrator.

  5. Flash recovery onto your device:

     fastboot flash recovery your_recovery_img.img
    
  6. Now reboot into recovery to verify the installation:
    • With the device powered down, hold the Volume Down and Power buttons until HBOOT appears, then release the buttons. Navigate using the volume keys and select RECOVERY using the Power key.

Installing LineageOS from recovery

  1. Build a LineageOS install package.

    • Optionally, download 3rd party application packages like Google Apps
  2. Place the LineageOS .zip package, as well as any other .zip packages on the root of /sdcard:
    • Using adb: adb push filename.zip /sdcard/
    • You can use any method you are comfortable with. adb is universal across all devices, and works both in Android and recovery mode, providing USB debugging is enabled.
  3. If you aren’t already in recovery, boot into recovery:
    • With the device powered down, hold the Volume Down and Power buttons until HBOOT appears, then release the buttons. Navigate using the volume keys and select RECOVERY using the Power key.
  4. (Optional, but recommended): Select the Backup button to create a backup.
  5. Select Wipe and then Advanced Wipe.
  6. Select Cache, System and Data partitions to be wiped and then Swipe to Wipe.
  7. Go back to return to main menu, then select Install.
  8. Navigate to /sdcard, and select the LineageOS .zip package.
  9. Follow the on-screen prompts to install the package.
  10. (Optional): Install any additional packages using the same method.
  11. (Optional): Root the device by installing the LineageOS su add-on (use the arm package) or using any other method you prefer.
  12. Once installation has finished, return to the main menu, select Reboot, and then System.

Get assistance

If you have any questions, or get stuck on any of the steps, feel free to ask on our subreddit, or in #LineageOS on freenode.