It's not hard to remove...
You have to remove these items in order. Back rectangle panels behind seat, side rear bulk panels, side bolsters, center speaker cover, long rear bulkhead, seatbelt panels, and front pillars from dash to headliner. Also sunvisors, middle sunvisor, and dome light which is actually hard to figure out and I forget but I'm sure shawn will chime in.
Headliner is attached via a few clips but 4x screws in each corner.