Change time domain controller

The time of our Domain controller is running 10 minutes ahead. So we need to set the time 10 minutes back and sync with e.g. an correct external time source. What are the consequnces on windows 2003 4 node cluster with sql 2000 and exchange 2003 ? Are there any procedures to do this without bringing down the whole cluster ? And what will happen with kerberos tickets on the network, because the time difference in a kerberos ticket cannot be more than 5 minutes...