My Trackball Fell Out How Do I Reset My Blackberry Back To Factory Settings? (no Trackball)?

How do I reset my Blackberry back to factory settings? (no trackball)? - my trackball fell out

The scroll wheel is certainly on my BlackBerry 8320 (not if dropped on the phone, can not replace it), then I sold it, like it on Ebay and now I get it back to factory settings, erase it completely and start to a new system. I have seen all the options - Settings - delete addresses, but I can not navigate without the scroll wheel, so that's another way to do this? Perhaps a reset button? Thank you to everyone who knows.