I was able to remove the two nuts that I saw (not easy to get to, but I did it), but even with those two off, the vent didn't want to move. My inspection mirror revealed a third, lower-most nut that still needed to come off. Not gonna happen, at least not by me today. For any of you that have had all three nuts off, confess! When you put it back together, did you put all three on? Really?