MAke sure all your moldings are removed, then cut away interior lip of windshield and backlite weather stripping with a razor. Now, gently push from the inside top of the windshield or backlite, and it will come out. Be sure to distribute your pushing, not just in one spot. If there is a hang up, push at that part. Do not pry at the windows with a screwdriver, it will break.
Now remove the old headliner, and number the bows, don't mix them up. Replace them in new headliner. The new headliner will be too wide for the bows. Don't cut anything yet, but slide healiner on up to expose both ends. Put bows in car from front to back, clip front of the headliner to windshield opening at center. AT the last bow, there are two hooks coalled headliner-support retainers. Be sure they are there in front of the backlite opening. DOn't hook the rear bow yet to them.
Now, find the cinter line of the headliner and lign this with the centers of the windshield and backlite openings. Clamp the center line in place at both the center windshield, and center backlite openings. Then STart at frontmost bow and move to bow #2. Then slit #1 listing about 1-2 inches back. The idea is to work out all the excess bunching. Continue this untill you reach the back, and then go back and work it untill all the wrinkles are out. THe headliner should be smooth, not tight.
Now use weatherstrip adhesive and apply a light coat to the healiner seam at bows #2 and #3 and outside lip of door opening. Pull tightly on the seam at bow #2 and press the cemented surface to the cemetned door lip. Do the same with bow #3.
Now go to bow #2 on the other side and do the same, then with bow #3 on the other side. Then repeat process at bow #1, be sure to alternate sides, to work out center wrinkles.
With bow #4 is a strip with metal prongs. Hook healiner on those prongs. Now hook the headliners support retainers through the listing, and over #4 bow.
Now start at the windshield and pull tight and cement center of windshild and glue outwards, then do backlite opening the same. Then work on sides of car. Trim all the excess left.
Thats it. If you have any questions e-mail me.