This answer was provided by Mattman (mdrobel@novell.com) in an
    article posted on comp.os.netware.security.

    If you don't have a backup, you can do two things:
    
    1. Reinstall Directory Services. I would recommend this option only
       if you don't have a lot of NDS objects and rights set up.

    2. If you have another user with Admin or equivalent rights, it's
       easy to recreate the Admin user object and give him the rights
       he had before. Those rights would be:
       Make him a trustee of [Root] and give him supervisory object and
       property rights.