Replacing a Rocker Panel

I have essentially started over on getting the cab level again because I need to replace the rocker cover driver side.
You may recall that I welded 2 pieces of angle iron to the old battery box & wedged up on the rocker / floor board.
I have the front rocker almost cut out fully.
The cab is low again & the door won’t close (it hits the door plate.
Looking at my pictures, do I just need to cut old floorboard off to remove the rocker panel? It appears to have been welded.
The inner panel appears strong other than at the lower end, so I thought I’d weld more metal to it to help support the footwell panel. ???
I don’t want to remove the fender so I’m doing a lot of extra work so it appears.
So most of the structural support seems to be from the rocker panel & it’s attach points along with the inner side panel.?
Thank you for your support!
Floor pan is the 1 st picture.
Attachments
IMG_3481.jpeg (245.97 KB, 143 downloads)
IMG_3482.jpeg (271.98 KB, 143 downloads)
IMG_3484.jpeg (256.58 KB, 142 downloads)
IMG_3488.jpeg (153.72 KB, 142 downloads)
IMG_3490.jpeg (234.34 KB, 142 downloads)


1953 Chevy 153A 3/4-ton
Working on my project since 2015
Follow along in my DITY