A master reset is the last resort for troubleshooting. This reset erases all data and restore preferences to factory default specifications. Performing a master reset is only recommended when the existing data has been backed up or is unwanted.
From the main screen, press OK.
Select Settings & Tools.
Utilize the 5-way navigation pad to highlight and the OK button to select.
Select Phone Settings.
Select Security then enter the security code.
The default code is the last 4 digits of the phone number.