AD and Exchange 2000 Name Change

Current Setup:
1 Windows 2000 DC with Exchange 2000 Loaded
SP2
All Hotfixes

Situation:
Company ABC.com was bought out, now need to change Domain Name information to match new company name, XYZ.com. We need internal name space and smtp addresses to match new domain name. Can not DC promo down because we need to keep all objects.

Can this be done? If so, how?