[bestatchess]

They just bolt on. The instructions say to jack up the back end, support with jack stands, remove tires and then bolt them on. JetTech indicates that tire removal is not required, just crawl under the truck and bolt them on. If you look at the photos in JetTech's first post, you can see exactly where to mount them under the existing leaf springs. Jacking up the truck would take the pressure off the original leaf springs, making them more straight, less curved. But apparently the original springs are straight enough with the truck on the ground that jacking is not required. If you look at the more curved springs in the drawing on the box, you would probably need to jack it up and remove the tires to mount on those type of curved springs.

If you rotate your own tires (swap front to back every 7,500 miles) that would be a convenient time to install.

One further thought, you could use some thread lock compound (locktite or permatex) if you were worried about the nuts coming loose.