90Q Removing bolt from rear diff mount. Difficulty

[TWFAUST at aol.com]

I am trying to replace the bushing in rear mount of the rear differential in 
my '91 90Q (same as 4K). I cannot get the bolt that goes through the rubber 
bushing out, so I cannot remove the mount itself. I have tried WD-40, PBlaster 
and whacking it with a brass drift and a BFH. The bushing itself had almost 
disintegrated, by levering against the subframe I can lift the mount 3/4" with a 
screwdriver. I assume the center "barrel" of the bushing is frozen to the 
bolt. If I put a socket on the bolt, it turns.

Is there something I am missing here? I think I can get in there with my 
sawzall and cut it. Is a new bolt available?

Tom Faust