That part sticking up there is the mast(or what is left of it). If you remove the black plastic nut,you should be able to twist it out of the base. It just has a smalll taper that the nut secures down into the base piece. You should be good to go as long as it comes out ok. Once the fender is back on you then put the chrome bezel,mast and nut back together. I sorta cheated and used clear silicone on the chrome base when I put it together. That way you can remove the plastic nut and mast to put on a car cover without scratching your paint every time you take it off.