I just went though the same problem. It's caused by the bolt rusting itself to the sleeve in the bushing. Had the same problem with the torque rod bushing.
Tried a sawsall and only ate up blades because it's a hardened bolt. Finally broke out an angle grinder with a thin cutting wheel, pushed the spring over as far as I could and cut the bolt. I repeated this on the other side of the spring. Make sure you have a full tank of gas before grinding!!
I lubed up the shanks of the new bolts as well as the bushing sleeve with moly coat. New bolts (2) from the dealer were about $8. Couldn't quite torque the passenger side without removing the fuel tank.
Had to replace the rear shackles also because the shafts were pretty well rusted away. The shackles are sold as kits for $45 each at the dealer and include the bushings, nuts and washers.