Headliner install with glass in???

If the vinyl top is still on the car and/or yje windows have never been resealed you may have issues like rust you've not yet seen.
You may not have water leaks now but in peeling the gaskets this way and that way installing a headliner and a top you might cause a water leak.
My 67 notch back had a very slight water leak at the bottom of the rear glass into the trunk, and the headliner had water stain above the sun visors meaning the headliner was wicking water at the windshield gasket.
You probably will need to replace some of the steel and plastic trim clips.
Then how old is your windshield or how clear is it ?
I wont say the way I did it is the best way but ... I did this for myself and the future owner of the car ( grand daughter ).
I accumulated parts for a very long time. I did it all and did it right.
Removed the dash and resealed the cowl ( vent boxes and wiper pivots ) Shiny new windshield too. Yes it was a LOT of work but well worth it in the end.