First
switch off mobile phone.
Remove
the battery in the mobile phone & re insert battery.
Press
and hold mobile phone in Call Key +Volume up key +Power Key in few seconds.
Now
you can see Android Logo on screen then press the call key to see recovery
menu.
You
select wipe data or factory reset or press center key to confirm.
You
select yes or delete all user data and press center key.
After you reboot the mobile phone set end the process
After you reboot the mobile phone set end the process