to do it OEM right, you need to pull the gasket. There are Dragon teeth up there that the headliner pulls over, no glue needed. Probably thee worst job on the line, my fingers hurt for days and I just did one! Pulling gasket and rear window is not that hard, pull lock strip and get in there on your back with your feet up. Push up at the upper edge and itll pop right out, just have a friend to catch it. Installing is a little more involved, set it on there and run the gasket lip over the window with a plastic spatula. Keep working around and the window will set right in, install lock strip and your done. Hardest part of headliner is getting corners not to bunch up. Ill pay a pro next time.