I just added lift shackles to my wife's rig this past weekend, so it is pretty fresh in my head. You need jack stands on the frame in front of the front leaf spring mount. Be sure to get it as high as you can so you can use the jack to raise and lower the axle to make install easier. Be sure to soak the bolts, especially the one mounted to the frame for several days before removal. Use PB Blaster, not WD40, because that stuff actually hold moisture and promotes rust. You need a 21mm socket and wrench. You will more than likely also need a breaker bar to get them bolts started. It is too difficult to fit an impact gun in there when removing the stock shackles, and is not really necessary, except maybe to speed up the process when bolting the leaf packs back up to the shackle. I suggest getting a bottle of anti-seize to apply to the bolts once you remove them, to make removal of these bolts easier later down the road. You need a big crow bar or something similar to help manuever the leaf packs around, because they will probably not want to line up when you get ready to bolt to the shackles. Also, tighten the bolts when down, but don't overtighten. The shackles need to be able to move back and forth with compression and depression of the leaf packs to allow more flex.
Hope this helps. It is fairly simple and can be done by yourself, although help is nice. Took me about 30 minutes to do mine, but I have done it before, so...