Share permissions after "migration" W2K to SBS 2008

I'm moving from Windows 2000 Back Office Server to SBS 2008.  Since there's no direct migration and I'm dealing with less than 25 users, I decided it was best to recreate the user and machine accounts manually.

I began by removing A.D. from the PDC (backed it up first!), then brought the new SBS PDC online.  I unjoined the W2K member servers from the old domain, then joined the new SBS domain.  The problem this caused was in shares.  The share permissions still showed the GUID for the old domain's users.  I tried to remove these perms but they keep returning.  Also, users with perms from the new domain aren't allowed into the shares.

I'd like to know if I unjoin the old domain first, then remove A.D., then join the new domain, would this correct the share permission problems?  Or, do I need to remove all shares/perms first, then unjoin the old domain, then remove A.D., then join the new domain, finally re-sharing?

I'm back to the old domain now (restored A.D. and rejoined the old domain) but it's a huge time waste moving back and forth between old & new domains so I'd like to keep the experimenting to a minimum.