These stupid thinks are a PITA X 1000. I have sprayed pb blaster, heat, broke a snap on punch. I may have to drill them out.
Drilling them isn't bad. Just use good quality drill bits. Trigger the drill on and off with pressure.
That keeps the bit cool. A lot of people grab a drill crank it wide open and smoke the bits.
Did you chisel the heads off yet? I found drilling the heads before chiseling them off, made things go easier.
I found it much easier to gauge my depth and work my way up to 1/2" or so - staying above the control arm with the bigger bits. I like to start with a 5/32.
As long as I was confidant that I got my hole centered, I would drill through to the top of the bottom part of the rivet head. You do not want to drill completely through. You have to have something to whack on.
Once you have the heads off and can see your hole - you might have to warm it a little or sand it - depends on how bad you mar up the top of the control arm knocking the heads off.
Then you can drill through to the top of the bottom part of the rivet head. Don't drill all the way through. You can stay up about 1/8". The rivets are not that hard and drill fairly easy.
Keep up sizing drill bits until you get to the point that you have removed one side of the rivet.
If you are well centered, you can quit when there is very little rivet left inside the hole.
At that point what is left of the rivet will be very thin. Warm it up a little if you wish. - I had one that I could have drilled up another size or 2. But I warmed it up and it came right out.
If you do not have an air hammer a regular hammer drill, set on hammer only with an old 3/8 bit or something will work also.
Something like this Bosch SDS hammer drill. Dang I can not believe I sold one of those brand new for $50
https://www.grainger.com/product/54...3837!&ef_id=Ws267wAABogCTxME:20180419155943:s