Nope, you guys missed a few things. First, it's called a crush collar, and as it was already said, you absolutely have to replace that, since they cannot be re-used once they've been crushed once. Secondly, you have to replace the old pinion seal. Again, this is something that cannot be used over once it's removed. You also need to replace the large pinion bearing. The small pinion bearing can be used again as long as there aren't a lot of miles on it, and it looks good. However, the big pinion bearing has to be pressed off the old pinion in order to get the pinion shims that are underneath it which should be used for the new pinion if the new ring & pinion gears are also the Ford brand. And when the clamshell tool is used to remove the large pinion bearing from the old pinion, it will likely bend the bearing cage atleast a little.
So even though both the large and the small pinion bearings can be used again, it isn't wise to use the original large one. So you'll need one of those rear end rebuilding kits which include bearings, marking compound, pinion shims, and a pinion seal. I disagree w/messing around w/the axle bearings unless the car has over 30K on it, or the axle bearings were making noise. It really isn't needed. And if the bearings in there are good, you're better off not taking the risk of removing them only to have a defective new bearing installed, which will have to come out after the job is finished(it happens sometimes). The same goes for differential bearings. If they look good, and the car doesn't have a lot of miles on it, leave em alone.
I did this job twice on my Marauder. The first time was to install 4.10 ratio gears in the rear, and the second time was to install 4.56's since i wasn't satisfied w/the 4.10's. The first time I performed it using a lift, and the second time I did it on my back w/the car on jackstands (a lot of work!!!). The second time I couldn't leave well enough alone, and I had to be Mr. perfectionist and remove the differential (aka "carrier") bearings also even though they were fine, and didn't even need to be replaced. Which only opened up a can of worms(long story!) and made things more difficult for me for no justifiable reason........... if your car doesn't have high mileage on it, then just replace what you need to. It's standard procedure to replace the large pinion bearing, pinion seal, and crush collar. NOT the carrier bearings, nor the axle bearings, nor even the axle seals(unless there was a problem, or the bearings are pitted). You don't even need to replace the bearing races either unless they're pitted or scored.
Ofcourse, a new pinion nut, and new ring gear bolts should be used, but those come w/the ring & pinion gear set anyway, and any competent mechanic who has performed the job before should know that.