How do I remove a user from the BES?
From BlackBerryFAQ
[edit] How-To :: Remove User from BES
1. Open BlackBerry Manager.
2. Highlight the Domain in the left pane.
3. Choose the All Users tab at the top of the right-pane.
4. Either search for a particular device by using the search fields at the top of the right pane, or scroll through the user list to find the user account.
5. Once the user/device has been located, highlight the user and right-click to bring up the actions menu.
6. Choose 'Delete User' and then hit Yes on the confirmation dialog box that results.
7. User will be removed from the BES.