When I re-did my 86, I used the following method:
- take the roof panel off and turn it upside-down on a blanket or carpet.
- get a plastic drywall mud knife or similar (plastic, not REAL flexible, thin) and work it all around the edge of the headliner, prying slightly. You may need to go around two or three times, but mine popped out after the first turn around (except for one stubborn area).
- peel off the old headliner cloth and try to rub off as much of the old foam as possible without damaging the backing board
- buy a can of "Heads Up!" headliner glue and two yards of headliner material (available from many fabric or craft stores)
- lay the backing board on the headliner and draw an outline about 2" bigger than the board, then cut it out.
- fold the corners of the material around the board, one at a time, and cut out pieces of the edge to allow for folding and overlap.
- lay the backing board down, spray the Heads Up! on it, and place the new headliner (foam side towards the board

) on it. I had to work from one side to the other, while some say work from the center out.
- flip the backing board over and fold the corners; glue them in place with a LOT of adhesive.
- after the glue dries, spray Heads Up! on the back of the backing board and press it back into the roof panel.
Should be good to go after that.
[RICHR]