I was digging around in my rover today and what did i find?

A hole....a big hole under my sill on the drivers side back.Its running down the weld a ways.So i cleaned it up sprayed it with some anti rust paint till i can tackle it myself.Anyone ever cut and replace the floorboards on that spot.Looks a bit complex to me.Mechanic stuff im good at.But i dont even know where to start with body repairs
I wheel alot so im not surprised.It doesnt need to be pretty.This rovers going to be four wheeling when i get another 95 classic.Sso please throw up your suggestions
Any tips would be nice....