Replace rocker?

[Bob66K20]

I am also at the beginning of the rust eradication in the rocker area at the bottom of the "A" post. Can these repairs be done without cab removal? I'd like to remove the fuel tank, door, floor covering and seat only. Is it possible? My rocker is perforated from A post backwards about 6 inches underneath the rocker vanity cover. I have similar rust on the passenger side but not quite as much perforation.