First, make sure the door is lined up in the door opening, gap between the front door edge and fender, etc. is where it belongs. Then look at the gasket that ends near where the wing starts. Under that gasket is a bolt that locks it in place. Also on the inside upper part of the door near the remote mirror adjustment knob, there's this little piece of round plastic that looks like the end of a Bic pen. Underneath that is an Allen head screw that also locks down the wing. There's a pin that bolts to the bottom of the door that the window track, which is part of the wing, sits on and gives support from the bottom.