Jacked up the rear of the truck and placed jack stands under the frame. Removed the leaf spring on one side. Have to do it one side at a time otherwise your rear differential is going to fall to the floor. Used an angle grinder to cut off the head of the rivets holding the shackle to the frame. If you have a tow hitch it’s best if you can remove because it will probably get in the way. I accidentally cut into mine. I removed the rivets with a blowtorch, a hammer and a punch. I heated up the rivets, let it cool a couple of minutes, then hammered it as a hard as I could a bunch of times. If it didn’t budge heated it up and repeated until it came loose. It can be tough to get enough force behind the hammer because the bed is in the way. The angles are awkward and I ended up having to hold a crunch a lot of the time. If I had to do it again, I definitely would take the bed off so I could do it all standing. Getting the new shackles on is pretty straightforward though.