Without Pc you Can do this :
Erasing the data with the Wipe Handheld option
Go to Options.
Then go to Security.
Then go to General Security.
Click the trackball and choose Wipe Handheld.
Then choose Continue.
Then type blackberry and all of the data should be erased.
To Using PC connection you can do this
Erasing the data and applications
First connect to Desktop Manager on your comptuer.
Double click the Application Loader icon.
Click Next to go through the Wizard.
When asked for your password type in an incorrect password and click Next. You will need to do this ten times.
Then choose Close. The device will become unresponsive in a 507 error without any software.
To re-install software open the Application Loader and choose the software or applications you would like to install.
Clearing device databases
Connect to Desktop Manager on your computer.
Double click on the Backup and Restore icon, then choose Advanced.
Select all of the databases while holding down the Shift key, and then choose Clear.
Then choose OK and all databases will be erased.
Then choose Close. blackberryvsiphone.com