So I know you can just 'change' the name. But here's the problem that i've encountered: Things break. Let me explain...
Remoting to unrelated computers won't work, and go to another computer instead. Pinging a computer will ping a different computer.
I'm guess DNS problems.
So I guess the other method is to leave the domain. Change the computer name. Rejoin the domain.
Why do I ask Techexams? Because this is the best think tank I know of