Here is a link to over 100 picture of a Headliner Board that has been pulled out and processed to be recovered.
landrover Discovery Series I & II Headliner Replacment pictures from friends & fun photos on webshots
I would recommend removing the:
1) Visors & Visor Clips
2) All grab Handles
3) Front Plastic Console, once all the Philips screws are out and the console is dropped then and only then remove the wire for the front dome light, don't remove the clear plastic cover from the front much to much work, remove the wires only from the back.
4) Remove the front "A" Post
5) Open front and back doors, remove rubber seal from around the "B" Post, unclip the "B" Post Clips that hold the "B" Post cover to the Pillar. You can only remove the "B" Post Cover by using this method.
6) If you have a Rear Seat Belt in the cargo area you will need to remove it (17mm) to feed it through the Side Window Trim Panels
7) Remove the Plastic Rear Cover that are around the rear side windows, their are about they are held in with about 7 plastic push clips.
8) Remove rear dome light closest to the rear 5th door
9) remove the felt trim around the opening of the sunroofs both front and back
10) Remove the Rear Sunroof Switch located within the plastic console, behind it you will find a Phillips head screw that holds the plastic console to the Roof of the Vehicle, once this screw has been removed then detach the wire harness for the rear AC switch, Dome light etc.
11) Now your ready to remove the Headliner Board out the rear door 5th door.
12) Remember to Fold down both the rear seats before removing the board.
Email me if you need more info or cal me at 407 786-4090 if you need some tech support. Bill