Permissions Script?

Currently, my company is running SQL Server 7 on NT 4 (NT authentication). We are preparing for a move to Win2k3. As part of the server move, new domains will be created. An example of an existing SQL login via NT 4 is AlphaBetaCompany/bshaw. The new Win2k3 domain and proposed login will be ABC/bshaw.
I've queried sp_helprotect, sp_helpuser, sp_helprolemember. Just now sure what to do script-wise with the data. I've also generated a table script (less the table) using EM, and selected Users, Roles and Logins. I've edited the old domain name changing to the new. Just not sure what to execute, and in what order. Anyone have some advise/scripts for this new dbjournal member. Thanks for taking the time.