Find "Factory data reset"
Press the menu icon.

Press Settings.

Press Privacy.

Press Factory data reset.

Restore factory default settings
Press Reset phone.

Press Erase everything.
Wait a moment while your phone restores the factory default settings.
Follow the instructions on the display to set up your phone and prepare it for use.
Wait a moment while your phone restores the factory default settings.
Follow the instructions on the display to set up your phone and prepare it for use.
