My XJ's original 3" Rough Country lift included helper springs, and they (along with my original leaf springs) were good and truly trashed. I swapped them out for a "real" 3" leaf spring, and tried to find the best, quickest, easiest way to do the job. I think that was a success - very little grunting and groaning or even cursing. ;-)
My XJ is an Arizona car, and has no rust, so all the normal nightmares weren't in this video. I worked on doing things sequentially to minimize the amount of work and steps.
A couple notes about the lift / vehicle. When I did the original lift, the rear was more than an inch below where I wanted it (lower than the front) so I installed a set of "lifting shackles" that added (IIRC) about 1.5". With the new "legit springs", the car ended up being higher... and not really in a good way. I'm getting some vibrations, and the handling just isn't what it was before the new springs. I'll be swapping out my "lift shackles" for a new set of Moog k150405 shackles (stock length, which is about 3" shorter than the lift shackles).
Also, if your XJ has standard shackles, you'll probably have to drop the top shackle bolt to remove the spring, then take the lower shackle bolt out. With the lift shackles, the leaf springs' rear bolt is below any obstruction.