Here's what I do, the first part is obvious and you probably already know but here goes. Once you have the truck jacked up and placed on jackstands go ahead and spray down your u bolt's with rust penetrator and let them soak a while, put a jack under the pumpkin on the rear end and jack it up just enough to support the weight of the rear end. Next go ahead and remove all 4 u bolt's, then lower the jack and rear end down and away from the spring's, I usually don't have to remove the shock's to be able to drop the rear end below the spring's but on a 4wd you may have to. Anyway now that you have the rear end dropped down below the springs you can work on the spring's, there is one bolt in the center of the spring that hold's the pack together it's called a center pin. I suggest that take a wire brush to the threads and nut on the center pin's on each side to clean off the rust and dirt, next spray them down with penetrator also. Then I use some large C clamps, I use 2 10 in. clamps, but a little smaller would work, anyway place the clamps approx. 10-12 inches out on each side of the center pin then tighten the clamps down, at that point you can safely remove the center pin. I lock on to the round end with a pair of vice grips, and then remove the 14mm nut that's the size on a 2wd and remove the nut. Now that the center pin is removed you can slowly loosen your c-clamps and relieve the tension on the spring's and the they will be loose except for the spring clamps on the end of one of the secondary spring's, but you can take out several spring's with out removing those spring clamps. Reassembly is the reverse procedure, also the OE center pin does have some extra thread on it but if you remove to many spring's you will need a shorter center pin, and the same applies for adding spring's a longer pin is Req'd.
