Home Forums Hunting & Shooting Hunting Optics Stumped. So how do I get these rings off?

I want to put a new scope on my Son's Sears .30-06. New Glass is a Christmas present for him.

When I started on this tonight, I find that I can't get the darn rings off the old scope.
I do not know the brand of mount and rings, they are evidently as old as the rifle. It must date back to the sixties at least.
From the pictures here, can anyone tall me how to get the darn rings off?
They are solid, and only open up a tiny bit, like a 16th of an inch when you pull the screws.