Simply level the mount to your liking. Using a skill saw, cut a perpendicular cut on the back of the mount to be hung. Place the “L” bracket with the slot over the cut and screw it in place. Now take the wall bracket and attach it to the wall, perpendicular to the floor and screw it in place. (Make sure it is in the wall stud.) Then it’s as easy as hanging the mount on the bracket. Absolutely no rotation of the mount whatsoever it is sure proof!