I've changed a few of them, here is a basic outline.
Remove doors
Remove kick panels
Drill all welds out with 1/8 bit all the way through
Drill with spot weld cutter only going through the outer layer
Cut rocker on post about 3" below bottom hinge and pick spot up front to cut on post below hinge
Seems as the back it comes from behind the cab corner
Use air hammer or hammer and chisel to remove rocker
Cut new rocker panel so it will but up with where you cut the old one on the posts
Drill holes where old spot welds were about 1/4 or 5/16 to re-weld
Use some self cutting screws to attach and hang doors to test fit.
When the fit is good weld it back on.
Grind welds down and use body filler to blend back in.
Use seam sealer where rocker meets cab corner and in front of doors to seal cracks.
Should be good to go after that. Put the doors and panels back on.