So take out the intakes AND the strut bar in my case.

Yes. That's what I did and it worked perfect for me. It's tighter on the drivers side but it will slide in there straight. If I remember right you will need a couple of extensions up to about 32". Plus I had a two foot breaker bar. Just be carefull when it gives. Don't want it to slam into the motor.

Taking the stock air boxes out helped a good bit, but 4 out of 5 installs you'll have to break the head off the bolt to get the stock cats out. Try to use some sort of lubricant like PB Blaster or WD-40 and let it soak for a while. Make sure the car is cooled down, otherwise the bolts will still be expanded and you'll be setting yourself up for even more fail. If you're able to get the bolt a 1/4 of a turn, use more PB Blaster and try to hit the threads if possible and work your way back and forth.

If you have to snap the head of the bolt, so be it. It's not the end of the world and you can drill and re-tap. That's what had to be done on my car.

Mine was only a 30deg swivel and it was tight. I had no trouble at all with slipping on the driver's side. Passenger side was more of a pain. The O2 sensors came off easily with an adjustable wrench.
Forgot to mention that I was installing the stillen g3 at the same time, so the strut bar and intakes were out.

So would you recommend against going to a shop and offering them $30-$40 just to remove the top 2 bolts ?

I found that if you PB blast it on both sides when mildly hot and put a blunt point tip on a air chisel and vibro shock the flange around the outer circumference of the bolt, it will crack the rust in the frozen up bolt.

It can make the difference between snapping Vs unscrewing the bolt.

. Even if you snap the bolt, all you would have to do to fix is go to a hardware store and buy a new one right?

Are most of you guys who are destroying these bolts from up North where they salt the roads? Mine took a lot of torque but was nowhere near being damaged.

I think it depends on how long you've had your car, the longer you've had it the worse the install is probably going to be due to rust accumulation.

My car has 34k miles and has been owned and driven in NY through all seasons and I took mines off by torching it and having someone turning it counter-clockwise at the same time. Took some time and strength but it worked. I did this with an extension as well so I was able to keep my G3's in there

Quick question.. isnt one of the bolts permanently in the factory header? Aka welded to it on the top so its not removable? or is that the one that has a star fitting on the top which can be removed from the engine bay with an extension?

Mine is a bit stripped out so if it gets loose I want to remove that factory bolt, dremel out the hole a wee bit and use some heavy duty replacements.

None of it is welded and is removable. There shouldn't be any star shaped headed bolt down there.

I think the stud you are thinking about was in the cat, not the header. Once you convert to after-market it is just 3 straight bolts.

hit it a few times over the course of the next few days.

Pretty sure one of those is a stud that is in the header, maybe they left it from the OEM cat when they removed it?