Server 2008 R2, GPO

I'm upgrading from our 2000 domain to 2008 r2 and I had some group policies on a 2003 domain we use in another school. I accidently didn't change the path on the tables to point to the new domain for several groups, Now I cannot login using that group it says no logon servers avail. What is a easy fix for this it should be some easy editing. It overwrote the default domain controller policy and the default domain policy, It will not let me delete these policies. If I could, I wanted to start over and just create a new default policy. How can I delete this default policy or edit the tables to point to the new domain instead of the old domain path. Which one is easier and How