The following steps will erase all the information from your phone, if possibly try to sync your phone first.
1. Take the back panel off to expose the reset hole.
2. Press
Power to turn on the screen.
3. While pressing and holding
End, use the tip of the stylus or a small
paper clip to press and release the
Reset button.
4. Continue pressing and holding End until the
Erase all data? prompt appears.
5. Press
Up.
6. Wait for the progress bar on to fill up, then you can use the device again.