Tyan Computer GX21 - Manual (Page 26)

2.3 Installing Motherboard Components
18 Chapter 2: Setting Up
2.3.2 Installing a CPU, Heatsink and Air Duct
Follow these instructions to install a CPU, CPU heatsink and
air duct.
1. Remove the pre-installed air duct. Refer to the illustration
on top of the air duct to locate the 2 screws.
2. Pull the CPU lever up to unlock the CPU socket.
CPU socket under air
duct