Procedure
- Press and hold Power key (2 seconds) after that immediately Press and hold Volume Down until Android System Menu appears
- Select "Wipe Data / Factory Reset" from Volume Down button and then Press Power key for confirm
- Select "Yes — delete all user data" option using Volume Down key and Press Power for confirm
- You will see Wiping data...., Formatting /data..., Formating /cache... wait until finished
- Select "Reboot System Now" wait for device start in normal mode (note : Wait few minutes do not unplug battery)
- Congratulation you are done
