I have never fitted such a large panel before but it was very easy. I removed the heel panel by the spot welds and locked the height of the rear subframe with chocks of wood.
I removed all the spot welds from the front edge at the base of the bulkhead toe panels, left the front sub frame in place.
Cut out all the inner sills leaving as much as the outer and door steps.
From underneath I lifted the front onto the toe panels and then jacked up the rear and held it into place with the 4 rear subframe securing bolts, refitted the front subframe bolds which realigned the whole floor section into the original position.
Loads of spot welding and mig welding later and it was in place. It was a few quid but it fitted like a glove.
My shell is fully welded and primed now and I am now making good and priming all doors and the bonnet so I will post a load of photos in the next few weeks once I have stopped paint stripping,rubbing,sanding and priming.
Vic