remove the A, B & C pillar trims
remove the visors
remove the sunroof trim ring
remove the oh **** handles
at this point the headliner is only held in by the velco straps and the door weatherstriping. if you work it around the headliner you shouldnt have to remove the weatherstriping.
might be better to remove the front seats to be able to get the headliner out without creasing it. you will probably get it out one of the rear doors. you will have to bent it slightly, be careful.
if you don't want to remove the seats and the headliner you can still drop it and inspect, but it will be in your way, a lot.