EDIT
Headliner replacement PDF
I should have used 3M Headliner and Fabric Adhesive, the 3M Super 77 failed in two years.
Using 3M 77 I sprayed one side of the roof panel lightly side to side and then up and down. Do not spray both sides as this will bond at once and you could ruin the whole job. I immediately applied the material because the light layers got tacky practically at once and the ability to remove an area if it did not form to the surface correctly. Do not let the adhesive pool or it might soak through the material.
The hardest areas to get to fit are the areas where the outboard mirror mounting holes meet the A pillar area this area requires the most stretching of the material and hence the fabric is under a lot of tension and pulls away from the board. One side of mine pulled away unnoticed slightly but the mirror mount holds it down and is hardly noticeable except to me and bluecoupe who helped with the install.
The install is harder than the removal, I am really glad I had his help, so much so I let him install all the trunk panels after the roof was done, he did all that work for a light lunch. The upper roof panels are the hardest to install, bluecoupe found it easier to get in the trunk to do it.