Anyone know how to remove the vent lift knob on the Fantastic Fan? Most units I see have a screw in the middle of the knob you can unscrew and pull knob off. The 2 Fantastic Fans I have on my 2018 FWC do not have a screw? Not sure if the knobs are just pressure fit? I dont want to break something pulling and prying too hard. Im looking to access the back side of fan controls.