- This custom ROM installation guide only applies to OnePlus One.
- Verify that it is rooted and the bootloader unlocked.
- Charge up your device up to at least 85% battery level.
- Install ClockworkMod/ TWRP recovery tool, then use it to back-up all the data in your device.
- Download the correct OnePlus One USB Drivers.
- Enable USB Debugging. On Android 5.0 and above, go to Settings>>Developer Options. For devices running Android 2.3 or below, on the Settings >>Applications>>Development.
Android 6.0 Custom ROM Installation Instructions
- On a computer, download CM13 Android 6.0 Marshmallow custom ROM .zip file and Google Apps.
- Copy the Android 6.0 ROM .zip file to the root folder of your device’s SD card.
- Turn off the OnePlus One then unplug it from the computer.
- Long-press both the Volume Down and Power buttons to boot your phone into Recovery Mode.
- On the Recovery mode, click wipe button to clear your phone data.
- Swipe the Swipe to Factory Reset option.
- Go to the Recovery menu, tap Install the select the saved ROM .zip file in SD card root folder.
- Start the installation with a swipe on the Swipe to Confirm Flash button.
- On installation finish, select Wipe Cache/Dalvik option to avoid boot loops and errors. Then choose Reboot System on the Recovery screen menu.
The device will take a few minutes to restart. Thereafter, your OnePlus One should be running on CM13 Android 6.0 Nightly Marshmallow custom ROM.