Floor Pan Installation

Anyone have any experience replacing the floor pan in a 75 Dart? The olde one is out and now we're standing there scratching our heads discussing how to get the new one in. Decided its not going to fit thru the door opening, maybe thru the windshield opening...nope...very reluctant to chop up a brand new part and weld it back together.

Thinking we might be able to lift the car as high as we can and slide it up and in from the bottom?

Looking for hints or someone with experience who's done it before that could provide some guidance.

Thanks in advance