Safe to assume that the scope is still in the rings? That makes it tougher. The screws are probably Loctited. A big Weller soldering gun can be used to apply heat only the screw head, but not easily if the head is flush or below the surface of the ring flange. That may soften the Loctite enough to break them loose. Couple of things to remember, on a 4 screw cap, one may be tighter than the other. Unfortunately that's the one you need to break loose first. Then you have to alternate just taking a 1/8 turn on each until they both release. Then the screws on the other side of the cap will be much easier to back out, even with Loctite in them. If they are hex heads and are rounding off, you may be able to tap a driver with a Torx bit (not the little 90 deg thing that comes with the rings) down into the hex socket, and while tapping on the top of the driver, applying force to back the screw out.
If that doesn't work, you'll probably have to drill the screw heads off, remove the caps and scope, then heat the exposed screw shank and remove it with small vise grips. Sounds crude, but works when nothing else does. The drilling is best done in a milling machine for precise location and depth control. If careful, it can be done in a good drill press. Don't try it with a hand drill unless you have no other alternative. Real risk of dinging the scope and/or rings.
Just things that work for me. Hope it helps.
Tom
