Thats what I thought too. It has 2 round plastic clips, one on top and one middle, that pop in. The bottom side has a threaded bolt which you have to attach a nut on from reaching from the inside. Got all this but couldn't get the front edge to sit under the window gasket like it was originally. I paid $70 for the louver and don't want to f it up. I was already bending it pretty good while trying to seat it. Maybe it's time to give it another try...
Problem with having the louver off is water gets in the static air vent and pool inside the rear quarter panel. This is obviously a bad thing.