Mike,
I just did mine last week. The front ones you have to take the wheels off to get at so ya you have to jack the truck up. The back ones are ok to do on the ground but you will run into a problem on the rear passenger side shock (the one facing toward the rear). The rear sway bar doesnt give you enough clearance to slide the shock off the pin that it sits on down on the differential end. I ended up just clamping all the leafsprings together and removing the 2 U bolts holding that plate that the shock sits on. I pulled the plate off and was then able to remove the shock. As for reinstalling it, put the top end in first then just reverse everything...hold the plate back up to the bpttom of the leaf springs put your U bolts back blah blah blah...OR if you can get the rear swaybar off that might be easier...i couldnt get mine off because all the bolts are seized and coroded...it was just easier for me to drop that plate.
I hope this was useful.
-Will