I have a god awful rattle coming from the small, non moveable HVAC vent atop the dash near the A-pillar. If I put my finger on it I can shift it around, and if apply pressure the rattle stops. I want to remove it, and reset it, possibly with some silicon glue but for the life of me can't figure out how to remove it. I realize this may be a newbie question but any help would be appreciated. Thanks!