I read an write up on doing it and its something im in the middle of right now, Basically just take out the old headliner, its premolded sound dampening mat so dont bend it up, just take it out. I removed al the plastic trim and it lifted right out, there are some wide metal hooks that it rests on.
Remove all the old the sagging cloth.
Take a broom, sweep up and remove all the old crusty foam. Get it all off there. Youll have a hard time glueing the new stuff on there if there is some left over, it will just sag again.
Get some adhesive spray from walmart or wherever, elmers makes some good stuff, and get some standard auto carpet or maybe Crushed velvet if that fits you
maybe some gold tassels too lol.
Anyways, spray, stick on whatever you decide to replace it with, make sure the seams are pushed together well, the carpet I'm going to use isnt wide enough to cover it all in one shot. but it was 12 bucks at schucks so :thumbup:
After you have it stuck on there, trim the edges to match the pre molded headliner, cut out the domelights and all that, I'll be cutting my hole in the cloth smaller then the real hole just in case, but the plastic cover for the domelight in my 89 will cover any mistakes no matter what.
Speaking of domelights youll need to get new fastners to secure the housings back to the studs, at least i will, i had to bend mine to hell when taking it off... youll see when you get to that part. Easy to replace.
I havent finished mine yet because there are a few power wires to rear lights i want to run through there before i put it back in. Once I get those ran I'll finish it up.
Good Luck, hope this helped. IMO the 20 bucks that i have into this is better then anything else I could buy, that and its something that i DID and didnt just buy and toss in there. and thats really the whole point right?
~Ed