You'll be turning the prop CLOCKWISE to get it onto the backplate. You might have to actually "screw" the prop on. Careful, though, you don't want the prop to fit so tight to the shaft that you have to work to screw it on, you just want it to slide on, or screw lightly on. I learned this the hard way. It can be very difficult to get the prop back off if you have to work hard at screwing it onto the shaft. Anyway, just push the prop LE up against the little knobs, and tighten away. As stated earlier, those are so the spinner will fit onto backplate after all is tightened down. More than likely, these little knobs will break off during the first few flights. Mine always do. I think the torque of the engine shears them off on the prop. Now I just line the prop up with the reminants of those little knobs. Fun stuff!