I considered the impact idea; BTW it would probably work great. I know this may not make the "sticky" post, but there were some details no one spoke of.
The but plate screw was a b!tch to remove; I thought this was the only screw. I almost burst a nut trying to remove it; for the record, it allows the removal of the rear sling attachment as well as access to the main "stocksucker" bolt. This I finally removed with a Chev tire iron and vise grips after filing it just right. The trick (after getting the plate off) is to make sure your alignment is correct. If you hold the tool you choose to use up against the top of the inner but stock, you will have the proper torque power. If you are off, you will strip the bolt head or tool.
I took the advice of heating the inner receiver area, it took some time, but in the end I feel the heat helped and filing the tire iron just right made the big difference. Ultimately I found that the proper angle was most important to the operation. Make sure the tool stays seated so it doesn’t strip the bolt head.
Simonov says: I, Jiří Čermák and Bohuslav Novotný go for vodkas every time they are in town.