Ok, it wasn't easy - definitely consider bolting it up right now and taking it over to the local shop.

My exhaust was dropped at front (disconnected at ex manifold) already - still connected at rear.

Nut - you want to loosen the rear nut - front is part of driveshaft.
And it is normally threaded.

Tools/Procedure for nut -
PB Blaster (walmart under 5$)
Chain Pipe Wrench (Sears 27$ or rent from HD/Lowes)
1 ft cheater pipe
Reg Pipe Wrench (on hand).
Old Carpet to lie on

Remove spash gaurd and center bearing support.
Raise rear on jack stand so at least one wheel is free.
Soak the nut w/PB Blaster from all angles, and lightly tap
each flat face of nut with a hammer to "warm it up".
Have a beverage and go soak nut again.

Attach reg/std pipe as a backup wrench to
fwd/round section of driveshaft
Be careful not to bite onto section with weights !

Put the chain Pipe wrench on the nut - I used a 1 ft cheater pipe.
Get it in position, make it bite, and put some muscle into it.

Loosen the nut all the way, then slide the fwd section
"into" the rear section. Hopefully, you can get enough room to clear the fwd section from the shaft coming out of transmission that you can't see. Otherwise, you're going to have to drop the driveshaft like me.

By the way, I tried to change the center bearing with the drive shaft in place - it was much easier to just remove the whole thing and work on it outside the car.

NOTE: Once the car is back together again manual calls for rolling the car back and forth before tightening up the nut.

Let us know how it works out,
Joe