1. Jack up the rear of your truck, and put jack stands under the frame to let your leafs hang freely
2. take off wheels for easier access
3.knock off the ubolts next (or cut them if you can turn the bolts)
4.jack up the rear end off the leafs so you have enough room to slide your blocks in
5.make sure the pins in the leafs line up with the <A TITLE="Click for more information about slot" STYLE="text-decoration: none; border-bottom: medium solid green;" HREF="http://search.targetwords.com/u.search?x=5977|1||||slot|AA1VDw">slot</A>s in the block, and the pins on the block line up properly with the slots in your axle saddle.
6.put your new u bolts on, and tighten up the new nuts in a criss cross pattern
7.put your wheels back on
8.lower the truck off the jack stands
9. stand back and enjoy the install that you just did
This is pretty much how i remember doing mine...its very strait forward, not much you can screw up. if the blocks are angled, the angle points forward.
hope this helps you out
OH and with belltech blocks, they give you instructions with pictures, so its that much easier