I don't think you can. I was about to suggest using Pacifist, but as you've already tried it...well, maybe you can get it to work by installing one of Apples system updates (if you're not already completely up to date), but I think I would just grit my teeth and do a new system install instead - particularly if your "restore DVD" comes with an option to reinstall/update parts of your setup only, and not just the whole thing.