Replacement of shocks

Wheels don't have to come off and it doesn't matter if you jack it up. If you DO jack it up so you can crawl underneath, use jack stands for safety.

This doesn't typically apply to shock absorbers but for anything else you replace or loosen that has rubber bushings, the bolts should only be tightened when the suspension is at normal ride height. If you tighten bushings when the vehicle is raised up and the suspension is hanging down, you will clamp the bushings in that position. When you lower the truck, those bushings will be in a permanent twist which will seriously shorten their life.

If any of your shock absorbers have a threaded stud on top, which was common on the front, do not over-tighten the nuts. They should only be tightened enough to make the rubber isolators expand to the same diameter as the metal washers.