In Figure 11, you can see the clip that holds the cooler on top of the CPU (on the left), the backplate for socket LGA775 and AMD CPUs (in the middle), and the socket LGA1366 backplate (on the right). For use with a socket LGA1155 or 1156 CPU, however, there is no backplate.
The cooler is secured by four screws inserted from the solder side of the motherboard, shown in Figure 12. These screws hold four pegs on the component side of the motherboard, as shown in Figure 13.
After installing these screws and pegs, you need to install the CPU cooler on top of the CPU using the clip already shown in Figure 11, using four thumbnuts.
Finally, we need to attach the fan to the heatsink.