[gkesseru]

I leave the wheels on the ground.
Block front wheels. Disconnect one end of the shocks, and remove the bolts from the springs. Put a floor jack under the crossmember and jack up truck to loosen springs.
Don't lift too much or else you'll harm the brake hose.
Use jack stands under the frame for safety before getting under. Using this method you can raise/lower the rear end of the truck without the springs in to measure what the shock travel is.