Kevin
I removed my u-joint on my 51 just two weeks ago. In order to remove the u-joint, you need to remove the floor over top of it. Sounds to me like you have already removed the 4 3/8" bolts from the joint, I would tap on the wing bushings lightly with a hammer and they should pop off the transmission joint.
If you want to remove the joint, then use a floor jack and raise the torque tube to the floor of the cab and remove the joint from the top.
Check out my webshots page, I did a small album for it....