I did mine with the windows in and used hardly any glue. I ironed the headliner with a damp tea towel over it, took all the creases out.
I also made a little drawing of the visors, mirrors and other fittings.
Marked the centrelines onto the front and rear glass with a marker that wiped off, also marked where the trim screws went in the same way.
Took any small creases out with an heat gun.
Mick