Perform a soft reset or a factory data reset of the device.
INSTRUCTIONS & INFO
POWER CYCLE: There are multiple ways to reset your device if you are experiencing issues. The first step is to power cycle your device. Press and hold the End Call/Power button, then press the Select button to select OK. To turn the device back on, press and hold the End Call/Power button until the screen lights up. Note: If you are unable to turn your device off, remove and re-insert the battery. Please see the Phone Assembly tutorial for additional information.
PERFORM A SOFT RESET: Press and hold the End Call/Power button for 10 seconds. The device will take a moment to restart.
PERFORM A FACTORY DATA RESET: From the home screen, press the App tray button.
Press the down directional button to highlight Settings, then press the Select button.
Press the down directional button to navigate to Factory reset, then press the Select button.
Press the down directional button to highlight RESET PHONE, then press the Select button.
Press the Select button to select ERASE EVERYTHING.