Na, with a little finesse and patience you can replace just the drive cups!! Tear the tranny down pull out the center diff and heat it up to 250 degrees. Whie holding it with a towel or gloves you can remove the screws. The heat will "melt" Lock-tite and the screws will easily come out, just be sure to use good quality Hex Drivers and be sure the hex driver is fully inserted into the screw. Remove both sides of the diff and you should be able to get to the e-clips.

Hope this helps some!