Hi,
This is how I got mine out of my 69 GTV, not sure if I did it the right way or if it was standard but it worked.
Seat base first, just lift from the front so it clears the stainless holders and it should just pop out - nothing holding it in but gravity and pressure from the front plates.
The back should pop out as well if you push it straight up. The bottom of it where it tucked behind the base should now be loose, if not check for some small screws or something. There are two locating pins that go stright down, near the edge at the top. You might need a rubber hammer or something to nudge it a little, but straight up to the sky.
My rear deck was not standard but was held in place by the seat backs and the rear seat belt anchors also held it in place, you might need to remove those.
Good luck, and it isn't that hard once you bend your legs and back to the right positions and work out the jigsaw puzzle. Try to have all the tools with you so you don't need to get in and out too often. The hardest part is getting out and straightening yourself again (I'm over 6').