I was looking for a guide to do them, mostly little tricks to make life easy. And Travis asked me to do a write-up on doing them, and since we're probably not the only ones, here goes. I don't take pictures when I work, use your imagination.
First off, plan to do this with an empty tank of gas.
Tools
Jack & jackstands.
Someway to support the tank on the jack, I used a chunk of 2x6 lumber.
7mm,15mm,24mm,11/16,7/8 sockets.
24mm, 5/8 wrench
1/2" drive breaker bar, 3/8" ratchet and a 16" (at least) extension.
Impact gun
An angle grinder, smaller the better. 4" worked good.
Good die grinder with a really good carbide bit.
Air hammer, with a punch.
Good old BFH
If you don't have the power tools, just stop. Don't think about doing it without.
Doing it
Jack the truck up, with the jack under the diff.
On my RCSB, I put the stands under the cab mounts. They just need to be ahead of the suspension.
Pull the wheels off, just makes life easy.
Time to deal with the tank, you don't need to drop it out just undo the straps (15mm socket, 3/8 ratchet, big ass extension), undo the filler neck in the bed (7mm socket, 3/8 ratchet), get the jack under it and lift it enough to take the weight off, grab the handle at the front of the tank and just start shimmying it towards the passenger side you only need about an inch and a half.
Drop the jack from under the tank (mine hung there on its own) and put something under it to support it. A milk crate worked tits for me.
Jack goes back under the diff, take the pressure off the springs.
Remove the bolts from the leafspring eyes (24mm socket/breaker bar or impact, 24mm wrench, air hammer/punch)
Drop the jack, letting the axle droop and pulling the springs out of the hanger with them.
Dealing with the rivets, 4 of them you can get with the angle grinder, 2 of them its the die grinder or torches. Knock them flat and hit them with the air hammer. You could do it by hand, and if you do I recommend unbolting the bed and sliding it back so you have room to swing a hammer.
And just like that the old ones are off. This will leave you with a bracket on the bottom of the frame, it's now not required. I left mine on, because I may use them as a mounting point for traction bars.
Install of the new hangers (I used McGaughy's)
First bolt the hangers to the springs, LOOSELY, bolt goes thru from the inside.
At this point it's nice to have someone to run the jack, I did one side solo. You can do without, just a pain.
Jack the axle up to get the hangers lined up with the 4 holes in the frame. You will not get all 4 lined up at once. Get one lined up and stick a bolt thru it, continue to adjust with the jack and the BFH on the hanger.
Bolt them in (11/16 socket, 5/8 wrench). As tight as you can get them.
Get the tank fought back into place and bolted up.
Cut half your bumpstops off, minimum.
Throw the wheels on (7/8 socket, impact, torque to 140 ft/lbs)
Drop the truck down on to the ground.
Tighten up the leafspring bolts, reason for doing it now is chances are they'd bind the springs with no weight on them.
Enjoy your truck that much closer to the ground.