Re: I've been in that situation.
An admin friend of mine once described the process for getting rid of nice techies in his old firm:
1. Take Unsuspecting Victim out for expensive farewell lunch and drinks.
2. Admin disables UV's remote access.
3. Announce during lunch that this is UVs farewell lunch.
4. Admin disables UV's Mobile phone account.
5. Admin trawls UV's logs to check for other accounts created by UV, nukes them.
6. Admin bins UVs user account, revokes Access card and ID.
7. Box up UV's possessions, place in lobby with security.
8. Place generous severance cheque in box.
9. UV returns, collects box, never seen again.
For techies that you *didn't* like, remove the words "expensive" from step 1, and, "generous" from step 8.
For techies that f**ked up, remove steps 1, 3 and 8 entirely, and carry out procedure after they leave work and what was then their last day...