Weld locations should be very similar if not exactly the same, if you guys have the same kind of car.

It will be stuck good until all welds are out.

Be aware though, that some welds may be slightly larger than the cutter or bit. So they would still be holding. Same thing if you didn't exactly center the weld, the edge of it could still be holding. Thats when a step bit would be handy. If y9u have them all drilled out and can tell that one or more are still stuck when you try to pry it off, try to see which ones are still stuck and dish out that hole with the grinder. Just a little, then pull on the brace more and see where the weld is stuck.

Robots weld it at the factory and as long as it passed inspection, a sloppy weld or two wasn't a big deal to GM. So you do find oddly shaped spotwelds, and they don't always quite fit into a 3/8 circle. Especially if the pilot wasn't centered. Thats one of the hard parts. Find you a good 90 degree angle pry bar of some sort and get under that brace so you can pry against the tower, because its not unusual to have to swear a bit getting a part like that off. Pry, grind, drill, cuss, repeat. Don't have your face under it when it pops off!

That flat-nosed bit I showed... they have 6, 8, and 10mm versions. On structural pieces like this, welds tend to be larger than the 6-8 mm and many times I'd reach for the 10mm.

Remember, its like breaking a single strand of wire by bending it, kinda. If you get the brace loose enough to move, rock it back and forth to loosen until you can eventually rip it off there. Don't worry much about bending the brace, you can hammer that flat on the ground after its off. They sure put a lot of randomly placed welds in it, didn't they? Thats overkill on purpose because sometimes the robot misses.

After the brace is off- theres an option to consider, let me explain:

You could weld up all the holes in the brace while its out, then grind them flat on top of it. Then you would have little or no drilling left to do because you would use the old weld holes in the tower. Plug weld it from inside the trunk and gravity would be on your side with the weld kernel. Since the heavy gauge piece is on the bottom, theres every reason to do it that way, but you would be in a very tight spot and up there by stuff that could burn or catch a spark. But man, it would weld up better that way.

The alternative is to drill new plug weld holes near the existing welds in the brace and leave all the holes you just drilled in everything. That means you end up with swiss cheese holes all around your strut mount that go all the way through to the trunk. Gotta seal those up, and hmm, did it get weaker? Maybe. Plus, you would be welding the thick lower brace to the thin upper tower metal while defying gravity with the weld kernel. Less than ideal.

I would probably end up doing as many from the top as I could. A guy could take out the speaker shelf and maybe gain some access from inside. Be sure to protect the back glass if you weld any up top. Wetted cardboard ain't bad for that.

Sorry such a long post, but I'm glad to share my experience. These bodies just don't rust much here, so I've never done one. Fixed plenty of bent W-bodies though.