How hard to replace are the rear shocks? And what is the basic way of doing it?

 

Easy, you don't even have to raise up the truck. But you should use an impact if at all possible.

 

It'll be easier with an impact but not necessary..Basically, just remove the mounting hardware at the shock eyelets then begin the struggle (it may seem as if they're permanantly mounted) to remove the shocks from their mounting points.

When going back on with the new, the nuts should have a self locking feature so locking pressure isn't on the mounts as the shock bushing needs to be able to float for articulation. I believe the mount bolts are 1/2" 13... A grade 5 bolt is sufficient.