Pitted & rotted rockers

Hey everybody

I've got a 72 Dodge Demon that being restored as we speek. Heres my sitution, the lower portion of the car from the back of the front wheels to the front of the rear wheels is rusted or pitted.

I replace the lower front 1/4s but the rocker on the paaenger side is badly pitted and rusted out at the back.

My question do I repair or replace the rocker. If I replace the rocker do I replace the whole part or just the lower portion below the door sill

The rocker on the other side is not much better.

Any advise would be helpfull