Turn Your Phone In Off Mode.
Press and hold Volume up & Volume Down Keys then Press and hold Power key.
Do not release any key until you see Recovery mood Factory Reset options.
When you see options Release all keys.
Press Volume up key to select option Recovery Mode.
Scrol down by volume down key to select wipe data and touch menu.......
Select yes delete all user data and touch menu again.
Wait and Select Reboot Device Option,
Now you done