Greetings and welcome to CB! You will need the company to release the device from BES. You will then need to call your carrier and provide them with the IMEI number of the device, found under Options > Status so they can initiate the device on a BIS for personal use.
Greetings nvgat and congratulations on your first post! In order to get rid of your email address, you need to wipe the phone, in essence, restoring it to factory defaults. To do this go to Options > Security Options > General Settings. Press the menu key and choose wipe handheld. You should be all set after that.