Cab corner, floor pan, cab mount, rocker panel HELP !!!

[olebluegmc]

Hi I am new to the site and new to truck restoration. I have a 72 c25/c2500 GMC (aka Chevy c20) I just got all my replacement panels but I am unsure where to start. I need to replace the driver side floor pan, both cab corners, both rear door pillars, both inner and outer rocker panels. I was planning to start on the cab corners first but I noticed they weld into the door pillar, what would be the best plan of attack to get it done correctly ? I have the cab on the frame and plan on leaving it on due to lack of space. Any help would be greatly appreciated !