Tony M,
It's a fairly straight forward procedure to remove the ball/bell from the shaft. First, loosen the collar (this loosens the seal) and slide the collar towards the rear. Then, slide the ball/bell to the rear. This makes it easier to remove the ball-joint rear yoke. Slide the yoke forward to remove it (this is often more difficult than it sounds). Once the u-joint yoke is off the driveshaft, the bell (and the collar) can be easily slid forward and off.
Jim Carter sells new and used ball/bell. Be sure the mating surface for the ball at the rear of the transmission is as smooth as you can get it (this area is often gouged).
Oh yeah, before you try to slide the bell/ball collar rearwards, clean the outer surface of the driveshaft as much as possible.
Good luck,
Tim
