[wrndln]

It is much easier to drill them out. I have done that to several frames. First I drill a hole about 2/3 through the rivet (center it pretty accurately). Next drill a second hole with a larger bit using the small hole as a guide. Lastly, use a drill bit just slightly smaller than the rivet and drill the rivet the third time. You can then knock the rivets out easily with a punch.
Rusty Nelson