Recovering a headliner is one of the easiest and most satisfying projects you can do. You take the old board out. It's brittle fiberglass most likely, so just be careful removing it. Gotta take out all of the trim around it, then any components that go through it, like dome light. Pull off all of the old material, it's just cloth with a thin foam backing. If there's crud remaining from the old foam remove it. (Mainly you don't want any lumps under the new fabric.) Repair any cracks or breaks. I just use paper or cloth and glue for this. Then, headliner fabric and 3M headliner adhesive. Start at one edge, like the back, and adhere the headliner material there. Once it's stuck there good, pull it back, and add adhesive to the whole rest of the board and fabric. Let it set for a minute or two, and then stretch the material from back to front. Don't worry about the curves yet, just get it nice and stretched, somewhat but not too taut. Then, start working your way from the middle to the side edges. Once this is done, turn it upside down and glue the flappy edges of the fabric to the backside of the board, making relief cuts where necessary. Do the same for any significant openings, like for overhead console or large dome light holes.