- You should first turn off the phone.
- Then press and hold together Volume Up + Power button, until you see Android logo second time.
- Now choose from the menu language "English", and confirm with Power button.
- From the menu in front of you select "wipe data/factory reset" using Volume Down + Power button.
- After that choose "yes", and accept this with Power key.
- Afterwards select "reboot system now".
- That'all.