There are 2 ways to rename Windows Server 2008 domain controllers:
Both methods are supported, but Microsoft recommends using Netdom command line tool because it reduces delay before clients can use the renamed domain controller (if you use GUI, you have to wait for AD/DNS replication to occur).
I've successfully used both methods, but on one occasion netdom command line tool failed to complete the rename operation, after which the domain controller lost trust relationship and was kicked out of the domain. This didn't cause any issues for rest of the domain, but I basically wasted few hours rebuilding the DC. I suspect this was caused by some orphaned remains of an old domain controller that had the same name. Not sure if "System Properties" method would have caused the same "lost trust" issue, but since then I stopped using netdom method and stick with System Properties.
Whichever method you use, remember to Update the FRS or DFS Replication Member Object using Active Directory Users and Computers.
Windows Server 2008 R2