Have never done it on a Ford product, Have done Dodge and some others.. It is not that hard of a job but getting the springs off can be a pain since the bolts are normally very rusted.. Last one I did was a trailer,, we had a ton of fun, Ate up a cut off wheel or two, but got 'er done.
Took the old broken spring to the spring shop, brought a renewed assembly back (Along with new shakles cause we damaged those too, not that they were not wore out already) and bolted it back in.. Two people, couple hours, Saved the poor guy a ton of cash.
Thankfully I have all the needed tools. And have done it before (4 times).