WAIT!!! There's a driveshaft support bearing that has to be unbolted first. Look at your car's frame. It looks like a big X. Look at the middle of the big X, and see the two bolts on the bottom. Unbolt them, and then you can slide the 2-piece driveshaft, complete with support bearing, out toward the rear.
This is true for '58-'64 Chevy passenger cars.