Changing name -Windows 2000 Child Domain

We have a network with a brand-new Win2k Root Domain, and an NT 4.0 local domain that was upgraded to Win2k as a Child Domain of the Root. The local company office now wants to change their Child Domain name, but we don’t want to lose the Active Directory information the Child Domain has. The standard method of changing a Win2k domain name is by running DCPROMO on the DC, demoting it to a member server, then running DCPROMO again and selecting a new domain name – and in the process losing your Active Directory contents. Is there a way of using the Root Domain to preserve the Active Directory users, computers, sites, DNS, etc. of the Child Domain while the renaming takes place?