Floor pan removal and replacement?

I'll be replacing the floor pans and trunk pan on my Duster and from what I understand they're just plug welded in.

Is there any reference material for body work like a structural repair manual or something? I need to know what I'm getting into and know all the attach points, etc. I have the 1970 Plymouth Service Manual, but the chapter in that for body work only has entries about the doors and glass and trim.

Wisdom and relevant data would be much appreciated.