Power cycle or perform a factory data reset on the device.
WATCH AND LEARN
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. 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.
PERFORM A FACTORY DATA RESET: From the home screen, press the OK button. Press the directional buttons to navigate to and highlight the Settings app, then press the OK button.
Press the left or right directional buttons to navigate to the Device tab, then navigate to and select Device Information. Navigate to and select Factory Reset.
Press the right option button to select Reset. Note: A Factory data reset will revert the device back to factory settings. It will permanently erase all personal data, preferences, settings and content such as pictures, ringtones and apps that are saved to the device. It is recommended that you save (backup) important data before proceeding.