Hey Milt!
Just another way to "skin a cat" and overcome the limitations of the tools available in a bodyshop and still end up with a virtually invisible repair.
I use the ever versatile 4½" grinder with a cut-off wheel to make all the cuts (it's laying on the lift runner in the photo). A pneumatic body saw is a handy gadget to have too.
That upper cut is not all that tricky since there is actually a gap between the outer and the inner panel. I just start from the back and work forward in 5" sections, keeping the cut-off wheel grinding back-and-forth over the cut until it looks like it's almost through the outer layer of steel. Then I just pull on it and it's tears the last little bit off, like opening a sardine can. It's pretty obvious process once you get the strip started. I've found a crowbar handy (and wood blocks to brace it against the heater tube) for those sections that need just a little more convincing to tear apart and stop for more cutting if it starts bending the weatherstrip channel.
This anatomy photo really shows how all the panels go together and what a "rot hole" the cavities inside the rockerpanels and the area under the heater tube are.
I'm always amazed at the amount of dirt and rust scales accumulated there and if any moisture is introduced, it can never completely dry out. By the time rust bubbles start forming on the outer rockerpanel, the inner rockerpanel is most certainly FUBAR as well and will need to be replaced. Then when you remove that, the outer section of floorpan is FUBAR and will need to be replaced. Next thing you know, you're on "the quest for a rust free ______ " (fill in the blank)!
