I just installed a new headliner in my 88 xj. I thought some of you might like to see the process. It was pretty easy. I bought some gray felt at Hobby Lobby and a can of 3M 77 spray adhesive. It took about 5 hrs total from start to finish. Just be gental with the fiberboard headliner as it is fragile.
headliner removed
fiberboard headliner
new felt glued to fiberboard
completed headliner
headliner removed
fiberboard headliner
new felt glued to fiberboard
completed headliner