Okay, let's come at it from a different angle. A picture they say is worth a thousand words. So lookey
here.
That picture was taken with the drivers door open looking straight down. You see the black conduit? What it is resting on top of is the outer edge of the floor pan on that side of the car.
Your not cutting nothing there, no need.
You drill the spot welds out here and separate the pan from the piece of sheet metal underneath.
Now then, from that same location start looking down toward the bottom of the floor pan. Along it's side and towards the bottom you will more spot welds. Drill them out and again separate the pan.
If you were to get the car up in the air and look at the rocker area from underneath you will see what is essentially a "brace" that comes off the inner rocker and "cradles" the outer bottom edge of the floor pan. It has what we might call "fingers"
Summing it all up, at the sides the floor pan is spot welded on top to this brace (where the conduit is by the doors) and on the bottom/sides.
Remember the objective here. You only want to separate the panel from the structural support. If you cut the support and don't have another to put in it's place, what will you weld the replacement panel to?
Since your not taking the tunnel out then the only "cutting" you need to do is on that side and maybe in the rear area (depending if your doing anything with the back seat part).
All cars that were every made the body is just a series of panels "stamped" out and spot welded together. If your replacing a "section" of a panel you cut. If your replacing the entire panel you drill the spot welds out and remove the panels.