turn off your phone and then remove the SIM and micro SD, then your battery and put him prendes but when you press the button ON / OFF, Press also the volume button + (plus) and wing you will enter android system recovery, then with the volume buttons on your phone down to the option that says FACTORY RESET, then press the HOME button and go to where it says YES - DELETE ALL oppress the HOME key to select the option, and you the option appears REBOOT SYSTEM NOW, back to press the HOME key. It appears that you are applying and then reboot and go.