Replacing entire leaf spring

They do that all by themselves! Jack up vehicle, support frame on jack stands, use a floor jack under the axle, loosen and remove u-bolts, spring shackle and front spring hanger, pull old spring out, install new one and re-assemble. Check torque on all fasteners after about 100 miles or so.

Hmmm...I seem to remember years (and years) ago when I replaced my Jeep springs with a 2" lift that we had to do some fancy levering to get them into place. I'm not lifting this time, just replacing. So you are saying it is just a bolt up job, eh?

Yes, that's about it. The hard part can be getting the old spring and shackle bolts out, they tend to rust/bond to the rubber bushings. Here's a writeup from a recent Toyota Trails TruckTech column:

Q. I just purchased a set of Smittybuilt nerf-bars for my 87 Toy-- The problem is the rear mount of the bar goes on the front spring bolt of the rear springs. I need to slide the bolt out of the spring 1/4 in so the nerf-bar will slide in place. The bolts won't budge. Anybody have any ideas how to get the bolt to move?? Thanks--Bill

A. Those bolts tend to rust to the steel sleeve inside the spring bushing. You need to break the grip of the rust to get it out. If its on the driver's side, try hammering the end of the bolt, leaving the nut on the end. Another option to try is some heat from a torch to heat up the bolt. Or try a thin pry bar between the spring hanger and try to press down on the sleeve while prying against the hanger and bolt head. Often you can get enough pressure on the sleeve for the teeth on it to dig into the opposite side of the hanger and hold it in place so you can turn the bolt and break it free. Some PB Blaster or other penetrating oil might help if you can get it into the sleeve. If all else fails, a Sawzall or cutoff wheel will cut the bolt apart to get it out, then replace it with a 9/16" SAE or M14 bolts.