Moving users, servers, cpu to new domain

Hey all…little question for you. I’ve got an NT 4.0 Domain here below a windows 2000 AD domain. We are going to be moving this domain under the Windows 2000 AD as a sub-domain via locations. We have three locations under the same NT 4 domain but are going to modify it to become location A.root.com, B.root.com, C.root.com.

What’s the best way to take these users, PC’s and Servers over to these new 3 domains WITHOUT, doing the upgrade path (I know it’s the best way but it’s not going to happen). Should I create a new domain called A.root.com with 2 servers and then move the users, PC’s, Servers that I want over to that one? Then do the same for B and C?

What’s a good tool for this, what problems could arise and if anyone could point me to some links of someone who may have had this problem as well I’d appreciate it.

Thanks,