So, apparently press-work is not my stong point. Definitely use a large socket that fits around the bearing cap. I experienced a lot of wasted time and irritation when trying to use the press blocks.
Also, WEAR SAFETY GLASSES/FACE SHIELD when using a press. I had one of the U-joint caps explode during removal and a piece of shrapnel grazed my face just below my right eye. That was one of those bone-chilling “oh-shit” moments.
When installing the new U-joints, the best procedure I found was to press the new cap in a little extra (with the press shaft) to easily pop the c-clip on. Then press the other side down until that c-clip seats. You should then have enough clearance to pop in the other c-clip.