Off Topic - Bolts holding Glass are stuck

I know it's a little off topic, but hoping someone here has similar experience and could offer some advice.
The door glass on my pellet stove was cracked so I had new pane cut at a local fireplace shop. He told me to bring the door in so he could get an exact measurement, and when I get there with the door I'm told they don't take old glass out. I now know why.
I picked up the new glass today, he even threw in a gasket. The old glass is held in by four metal clips that are bolted to the door. The top two came out no problem but the bottom two are seemingly permanently part of the door, thanks to years of heat I assume.
I tried a Gator Grip socket since i still had some edge on one side of head, useless piece of crap excuse of a tool only seemed to round off the edges even more and stripped the straight edges that I once had.
I tried wd40 let it soak in then heated with propane torch, no help. All I've managed to do is back one off at most 1/4 turn, in doing that the edges on the head are all rounded. The other bolt still has some edges so I'm afraid to do anything with that.
Any advice, comments, criticism?

Hmm. Some more things to try. Vise grips, More torch/heat, PB Blaster(spray really good, let it soak in for 24 hours while spraying it a couple more times), A proper sized six-pointed socket. I have something similar to this http://www.sears.com/craftsman-impact-driver/p-00947641000P that works well on frozen things.

WD-40/PB blaster and others. Soak it well then use a wire brush to remove all the caked on debris. If that does not work, a little heat will help from a torch.

PB blaster then smack bolt with a hammer to loosen up.

I just had to do the same thing with my austroflamm. I had to heat the bolts up spray with wd-40(it's what I had on hand) and whack them with a hammer to shock any crap stuck in the threads loose. I also used a 6 point socket and still had to work the bolts back and forth and kept spraying them till they finally came out.
Luckily on the austroflamm the bolts are brass so if they break they are easily drilled to easy out them. When you reinstall the bolts I'd suggest using brass if they already aren't and using some never seize so if you ever have to take them back out it will hopefully be a bit easier.
Worst case scenario you can probably take the door to a machine shop and they may remove the bolts for a fee.

Got a welder? Welder friend? Weld on a larger nut over the one trying to remove. The extreme heat and adding a shot oil while cooling usually shocks things enough to work the offending nut or bolt back and forth till its free. Good luck

X2 on the torch. Get it red hot, the threads expand and break loose.

Advice from uploaded Photos?

Just a reminder in reference to the above mentioned use of the torch....make sure you're heating just the metal part of the door frame AROUND the bolt....you want that to expand slightly to loosen the threads. Then use a good pair of vice grips that are snapped onto the bolt head TIGHT.

This thread does not appear to be off-topic. What size are the bolts? For the rounded ones, your best bet at this point is to use appropriately-sized vise-grips with sharp teeth. Work the bolts back and forth while adding a Liquid Wrench-type product. Slow going, be patient. Here is a trick from a vintage car mechanic: Heat the frozen bolt and rub candle wax on the threads. The wax will be wicked into the frozen part and free the bolt.

Thanks for all the great advice, finally got it last night. I wasn’t patient enough at first,
In case you're wondering what did the trick:
* Vise grips, as head was rounded nothing to grab with socket or wrench.
* WD40, have heard PB Baster was good but had WD40 and it worked.
* Soaked overnight with the WD40, blast before work, then when I got home gave it a couple good whacks with a hammer, another shot of wd40, heated the door not the bolt with propane torch a little over a minute, used vise grips when I felt it give a little wiggled it in and backed out until it turned free.