How to immediately terminate a SPID with a very long rollback time estimated?

I have a script to restore a database from a backup. Prior to the restore command, it has: set single_user with rollback immediate The script seemed to be hanging here. I used sp_who2 to find out a SPID number 70 was in ROLLBACK state. I then used kill 70 with statusonly to obtain estimated time remaining - and it translates to more than 20,000 hours. How can I arrest this rollback, even if it means the DB ends up in a transactionally inconsistent state? (I don't really care, as I just want to restore it from a backup.) Is my only option to shut down the server (and impact other DBs on that server)?