If the whole thing just spins one of two things has happened........1 - the prongs have sheared off (best situation) ---- just remove the bolt that was in it and push it out from the bolt side, it should just pop right off then replace with a new one. 2 - the prongs have spun around the piece they were embedded in effectively drilling out a very large hole ---- and that is a bear to repair as you have to fill in the fiberglass (I take it this was in a fairing from a previous comment) with all the attendant issues of strength, paint etc., then drill in a new small hole and put in a new fitting.
Hth
