subframe removal/cold welding?

[ekubota]

To install a new subframe and fiberglass tail, I have to remove the subframe. It didn't take long to remove the battery, tail plastic, unclip the wires, etc. but the fourth subframe bolt (lower, left side) is stuck. Either someone overtorqued it, or the aluminum and steel fused somehow. There's no rust, and the right side was tight but not that hard to remove. The left upper bolt was very tight and required a small breaker bar. The left lower head has partially stripped. I tried using an impact wrench with the 8mm hex bit but it doesn't budge, even after several applications of penetrating solvent.

Any suggestions? I have to finish this by Mon. night or give up and keep the stock tail for now, since the bike is my only transportation.

I will try a bolt extractor if all else fails, and I do have another bolt. I'd still like to do the least invasive method possible.

[Soul]

Try out this stuff called PB Blaster..Its this insane pentrating lube..I use it whenever i have a hard to remove bolt..I basically hose down any bolt that I cant get to budge..give it like 30 minutes and I hit it again and wait an hour..
On a 2" bolt when it gets unscrewed about half of it is covered in pb blaster..I think walmart may have it, schucks probably for sure...
I guess let me know how that goes, but it has always worked for me in shitty situations like that.
Welcome to the forums, btw.

[SVHUNTER]

pb blaster is good but i just found this stuff called freeze it. i have not found a bolt it won't pop loose.

[ekubota]

I'm trying another type of penetrating lube which I applied last night and will check in the morning, but the head is largely stripped at this point. Unless the lube makes a huge difference (I can remove the bolt with a regular ratchet wrench and one hand), it'll probably need a bolt extractor.

The hex head bolts that require a key and not a socket are really shitty because there is much less leverage and overtorqued fasteners tend to strip.