Re “IP’ing” my entire infrastructure

Hello. I am going to be leading a project to completely re-IP our entire infrastructure. We are moving from a 192.168.x.x/22 to a 172.21.x.x/16 subnet. The infrastructure is 98% Windows (2003 SP1 and SP2). Forest functional level is W2K3 as well.
We are a pretty small shop so I am not going to have to worry about different sites (we are located in one central location) I am just nervous that when I change the IP addresses of the DC’s my Active Directory is going to fail. Am I safe in assuming that if I change the IP’s of the DC’s first and then log in locally to the other servers in the AD forest I can manually change the IP and then reboot?
Has anybody gone through this before and can offer any advise?

thanks in advance