Mark where they line up & which yoke goes with which shaft when you remove. There are arrows that line up for the halfshaft reassembly if you disassemble the halfshafts for some reason, but some yokes also have weights for balancing, so take notes if you want it back the way it was. You can also reverse each halfshaft for more exhaust clearance if you want, if not already done on your car. As for the u-joint replacement, most probably press in the new joints with sockets & vise, but you will need something like that to get them to compress fully to get the circlips in. FYI, Precision Proformance has replacements with a button that allows you to monitor when the grease level is getting low (similar to an axle buddy on trailers). I had some fitment issues on some I bought from them (the circlips were too thick without milling down the edges of the end caps a tad), but they had solved that on the last one I got. Some other vendors may, too. This job is really not a big deal at all.