Help me please, Im stuck. LOL

I have been trying to remove some old ventitian blind holders, that are
from my best guess and terminology, is riveted into the metal window frame
on the insides.
Its those small retangular holders, where one side nearest you opens
up to insert the blinds.
I have tried everything, I can think of. Cant pry them out,
as the whole frame will start to move.
I have been able to cut the heads off of some of the rivets,
using a rotary tool, with a cut off disk.
A few I have been able to get my jigsaw blade between the
fixture and the frame and cut the rivet.
But I still have all ten of them on my five living room windows,
and the wife wants them off.
I cant get a hacksaw into it, but I can fit it in, using just the
hacksaw blade, using short strokes by hand, but it seems like after
countless strokes, I have just been tickling the rivets.
Any and all suggestions would be entertained and much appreciated,
as I need to get these off, patch the wholes and get ready for painting.

Much regards Jerry

If they're really rivets, you should be able to drill the heads off
with the appropriate size drill bit. Tom