So I'm trying to disconnect the single piece driveshaft from my transmission so I can get access to replace my clutch. The problem is theres a lot of general surface corrosion (rust) that's nearly fused the rear shaft to the mating flange where the bolts attach. I've sprayed penetrating oil all over it and have gone at it with a deadblow, but it won't budge. Any ideas?

 

If you haven't gotten it apart yet, try putting just a little heat to the flange and then take a small thin chisel and try driving it between the flange faces.