Hard way!? 
I had my code inplace long before ADMT2 and NetIQ was just starting out with their migration process. They just have the resources to apply to their processes to polish them. 
I have to admit I could have spent a few hundred thousand dollars on NetIQ products and licenses...
but migrating 12,000+ accounts from NT4 domains to other NT4 domains and now 30,000 accounts from NT4 to AD.
Unfortunately for this Kixer, my processes key on security surrounding the creation and use of a new user account not the moving of computer accounts and computers from one domain to another. We have always left the computers in their original domains and treated them as "resource" domains. The way we get computers into our W2K AD architecture is through technology refresh when we rebuild or deploy new hardware.
I would suggest exploring NetDom.exe. You can script the computer move to the new domain remotely and force reboots to activate the computer in the new domain. This could be scripted top process a list of target computers over the weekend.
