Well, you have to remove the rear seat, sail panels, dome light, sunvisors, and two push pins in the rear, then the headliner will come out.
I spray both the fabric and the headliner backing with the adhesive, wait about 2 minutes for it to tack up, then work the fabric onto the headliner. I recommend doing it in sections. Remember that once the fabric touches the headliner backing, it isn't moving, so make sure you don't let the fabric wrinkle when it lays onto the backing.
By the way, it looks pretty horrible in the picture (resized the picture and messed up the quality), but the headliner looks great in person.
-Rod