Unlock boot loader
If your phone already have this unlocked, skip this section.
- Install Android SDK and USB Driver
- Enable USB Debugging Mode. Goto Setting > System > About phone > Keep clicking the Build number until developer mode is unlocked.
- Go to Settings > Developer options, check the USB debugging.
- Before continue, make sure the phone have 80% battery charge.
- Switch off the phone
- Hold Volume Up, Volume Down, then press Power. Hold the three buttons for a few seconds until the green robot came out. This boot the phone to bootloader mode.
- Connect the USB cable.
- The step below unlock the bootloader. Unlocking the bootloader will ERASE ALL DATA and restore the phone to factory state. Backup your data first before continue.
Open a command prompt, input the command below (change the username in the path)
C:\> cd c:\Users\ray\android-sdks\platform-tools
- Use volume key up and down and select yes, press Power to confirm.
- Once the line “LOCK STATE – unlocked” shown in red, type the command below to restart the phone
- If phone does not reboot, long press the Power button. Wait until the phone reboot.
C:\Users\ray\android-sdks\platform-tools>fastboot oem unlock
Root the phone
- Boot the phone to bootloader mode again. (Switch off the phone, holding volume up, down and power button). Make sure the USB cable is still connected.
- Download CF-Auto-Root, and then unzip it.
- Use the command prompt and execute the command below
- The CF-Auto-Root only install the SuperSU binary and APK to the phone, nothing else. Safe and clean. You still have the stock recovery, should not affected future OTA.