On the pockets, cut them off the existing panel, use a grinder to carefully remove the old floor and weld them on the new. That is why I have saved all these, it works pretty well as they are not reproduced.
https://www.flickr.com/photos/advance-design_parts_co/8687676866/in/album-72157631868452754/
Trim to fit from here.
https://www.flickr.com/photos/advance-design_parts_co/43875862061/in/album-72157631868452754/