Removed tiny 3/16 hex head screws- difficult due to some rust and rounding of one hex head, and needing to bend back the very stiff metal tray to access the nuts. I ended up having to gently cut and snap the vent off b/c one screw would not come out. I chose to use 1/4 hex head #6 screws to affix the vent. I tested that they would not penetrate the plastic inlet and was prepared to file the tips in case. Another problem came with aligning the inlet's holes and holding it in place while attempting the re-attachment. Painter's tape was a good tip as shown in video, but it took some time. Lastly it's always a pain to reattach those custom faces.