Anyone had trouble removing these bolts. I have new to me 2012 DF300's with 350 hrs. Doing all my maintenance. Manual is not to clear but I think there might be some of the square zincs under these covers. Tried to remove these bolts and fear snapping off. They probably should have anti corrosion grease when reinstalled. Just hate breaking bolts If I don't have to. Anyone else had this problem?