Easiest way - download Javawipe (RIM app) and wipe the device. Backup your data 1st so you can restore what you need as you need it (selective restore).
You can download it here and simply follow the instructions -
http://www.blackberryforums.com/atta...der-v1.9.4.zip
You will have to use the DM to re-install your OS once this is done. I'd suggest you upgrade your OS at the same time to .440 (leaked).