First you need a quality contact glue. I've used the 3M product made for installing side trim--sometimes referred to as "monkey snot" by mechanics in my circle of friends :-) (it's yellow and very messy). The shorter piece gets glued to the rear opening of the sunroof (on the roof itself)--you sort of have to angle it down at the ends. The longer piece goes around the sides and front face of the sunroof panel--that requires removing the panel altogether. Follow the directions on the contact cement -- a small flat & stiff artist's brush is a good tool to spread the cement evenly--you may need a few to do the two separate steps of glue curing / installation. Keep a solvent handy to clean up over-use right away. Place the seals so the round bead is partially above the roof line--if you set it too low the panel may not close all the way. -- Dave