No problem. Hopefully everything works out for you. God knows I've been in enough hairy situations with rusty and frozen bolts after growing up in Massachusetts salty winters my whole life, doing all my own vehicle repairs and maintenance, and never having a garage. Better to err on the side of safety with bolts/screws/nuts that even start to indicate that they might strip the moment you think they might become a problem. Always keep fresh sharp screw drivers and 6-point sockets (not 12) and maybe consider buying a manual impact driver since that can really help freeze up frozen screws while simultaneously applying downward pressure to the screw. Also good to use Never-Seze whenever you can on any bolt that you (or someone else) might want to get off again at some point.

You mentioned that it's raining out today. I'm not sure if you have your Brake fluid reservoir open or some brake cables unhooked for the job, but make sure you flush in new brake fluid from a sealed container since that stuff soaks up water and humidity and becomes junk if exposed to the elements for even a short while.

 

I didn't do it yesterday but I actually ended up getting the bolt off thank God. My brake fluid is actually low so I ended up going to advanced and getting some more anyways. It's not raining anymore today so I'm gonna finish the job today. I got some anti-seize or whatever it's called also. I hope that nobody has to encounter this problem. It sucks big ones. Thanks again!

 

Rear calipers have gotten pretty cheap on these cars. You can pick up a reman caliper for under $40 on rockauto.com (plus your core).

I've had so many issues with my rear caliper slide pins seizing (common issue) that I end up just replacing the rear calipers whenever I see an issue with slide pins (which being in the northeast happens a lot to me)

 

Only reviving this old thread incase someone haves this exact issue and have found this thread in their search. If you're just needing the caliper off to replace the brakes you use a screw driver to pry it open by removing just the top guiding pin bolt. Replace the brakes, making sure to depress the piston before you set the caliper back in place. As long as you have the top guiding pin out, all you have to do is pull the caliper itself out. The other guide pin bolt that's stripped will pull out. It'll just still be bolted in the caliper itself. So you can leave that bolt as it is and lube the guide pin. Now if you need to replace the rotor, you'll have to remove both of the 19mm bolts that hold the bracket in place. I'm just mentioning this, because no one else has. So it's not the end of the world if a guiding pin bolt is rounded out or stripped atleast. You will still be able to replace the brakes or rotor. I just did this myself as I had a piston completed seize on the rear driver's side brake caliper. It was completed rusted, I couldn't even depress it in at all. I needed the caliper off so I could get the piston out to rebuild the caliper. As long as the bottom guiding pin bolt isn't seized up, it should just slide right out.