Asus Motherboard PR-DLSR533 - Manual (Page 32)

2-6 Chapter 2: Hardware information
2.4.3 Installing the heatsink
Follow these steps to install the CPU heatsink.
1. Carefully place the heatsink on top
of the installed CPU. The heatsink
fits in only one orientation. Take
note of the heatsink placement as
shown.
2. Use a Phillips screwdriver to twist
each of the four screws to secure
the heatsink to the motherboard.