Can't remove rear brake pad pin
 

I'm trying to change my rear brake pads. The whole assembly was pretty dirty because I ride in winter and can't wash the bike everyday...so I hosed it down with brake cleaner, scraped off all the crud I can get to, and am trying to break the pad pin loose.
It won't budge. I've even put a wrench on the end of the allen key for extra leverage.
I've banged on the bolt head with the allen key in it and on the back side of the pin trying to free it up. I've applied what feels like enough pressure to break it loose, but nada. I've tried to tighten it as well. Oh yeah, I've also applied generous amounts of penetrating fluid.
For anyone that has replaced rear pads, how hard was that bolt stuck.
If I break the pin it's game over for my rear brake assembly, and I don't want that.
Any suggestions? Is heat a good or bad idea?
At this point, I'm ordering a new pin and am just going to run my pads a little farther (they are so close to being done, like maybe by the end of the week!).
It's all my fault for neglecting her in the winter, I know.
Thanks for your help in advance.
Now back to changing my sprockets and chain.

Hum....this is all I know which you have probably tried...use pb blaster, every 30 seconds or so, tap both ends HARD with a crescent wrench or the back end of a screw driver. Then apply pressure for like 10 seconds. repeat, eventually the constant pressure will brake it loose.

Thanks Matt. I did try just what you said to no avail. I'll keep spraying it and give it a go in a few days.
I wish I had an impact bit for it. Might have to visit NAPA to see if they have a 5mm allen impact bit (if such a thing even exists).

I used a allen head end socket, but I don't think mine was that tight. If you get the socket, you can put it in a impact unit.
If you don't need to change it, keep adding penetrating oil to it for a while and do it after the next ride.

Sometimes "impacting" is the only thing to breakup the corrosion that forms between unlike metals. Got to get some kind of good contact to the pin.

Heat, followed by a spray of your choice of penetrant. A propane torch with a small tip. I'd be reluctant with any sort of impact other than the "handheld and hit with a hammer" kind. 5mm bit cut real short so there is no shank to twist. Don't damage the head of that pin.

I usually use blunt end punches to carry the shock, Kroil and heat -- the only things it did not work on for me, was stuff that was welded and was not supposed to come apart :D:D:D I fixed that however:p

I'll get on it with some heat added to the mix, wasn't sure it was a good idea. I guess I'll go get some new brake fluid and change it out after.
Thanks guys!
Happy New Year, may you all have many miles of epic and trouble free riding!