To mount aftermarket coolers on AMD motherboards, these plastic brackets often need to be removed.
Stock coolers for Intel processors use push pins that go through holes in the motherboard. We recommend pushing opposite corners in to evenly spread the thermal paste and to keep from putting uneven pressure on one side of the CPU  (just as you should do when screwing down any cooler). AMD stock coolers have metal arms that snap into notches on a plastic bracket on either side of the socket. To mount aftermarket coolers on AMD motherboards, these plastic brackets often need to be removed.