Question: Toilet Fill Valve Lock Nut
 

(Edit: Fixed. Needed two people. Was a bit of a pain in the ass but managed to get it free.)

Ladies and Gentlemen,

I'm trying to replace a faulty fill valve in one of our toilets. It is original from the day this house was built about 30 years ago.

In order to remove the fill valve, the lock nut at the base of the basin must be removed, however, it is stuck. I've tried to hold it with a vice grip while heating it with a heat gun and turning it with a rib wrench. No go. It's stuck on pretty damn well. The entire unit spins and it is stripped. Hurray.

Aside from cutting it with a saw, any other suggestions?

Thanks in advance.