I replaced my headliner in my '67 coupe. Even with the front and rear glass out was still tough! Getting it wrinkle free of course is your main goal! Check the rubber gasket(inside of course) around the glass to see if is still "rubbery", you'll need to be able to poke your new headliner material beneath the rubber. if the rubber is hard as a rock, you will not be able to accomplish it! Guaranteed! Personally I think it would be quite impossible! Do your homework bigtime before tackling it!

Also, pretty much everthing has to come out of the car to just even work! seats, rear seats, rear package tray, keep the bonnets in order!
something to consider: if ever wanting to install overhead console, this would be the time to do it! If installing 3 point seat belts, this would also be the time to do it! Think ahead!
dne'