Renaming a Windows Server 2003 DC using Netdom
I had a project that required me to rename a domain controller over the weekend. There are two ways to do this but I strongly suggest using Netdom if your domain functional level is Windows Server 2003 . Petri has a great writeup about this process so I recommend you check that out if you need to do perform the same process for yourself.
Petri link: Windows 2003 Domain Controller Rename
Microsoft Link: Technet Netdom article
I found that with a little bit of planning it was very painless and I was able to do it entirely from home which was a big win!
I definitely recommend thinking about it and documenting the steps beforehand. While you could do it on the fly spending a half-hour or so writing the process down made the evening go much easier.