1. Turn off the device.
2. Press and hold the Volume Up and Home button,
then press and hold the Power button.
3. When the Android logo appears, release all buttons.
4. Use the Volume button to highlight 'wipe data / factory reset',
then press the Power button to select.
5. Use the Volume button to highlight 'Yes -- delete all user data',
then press the Power button to select.
6. When reset is down, highlight 'Reboot system now',
then press the Power button to restart the phone.