To perform a master reset on the handheld, follow these steps:
NOTE: A master reset restores the original factory settings and can erase all downloaded content, including ringtones, camera images, contacts stored in the handheld memory, and Java™ applications. It does not erase data stored on the SIM card or memory card (if available). Back up all necessary data on the handheld memory before proceeding.
From the Home screen, press the Menu key.
Scroll to the Options icon and press the trackball.
Scroll to Security Options and press the trackball.