Abit KU8 User Manual page 11

Hardware Setup 2-3
6. On the other side, push the retention clip
straight down to lock into the plastic lug on the
retention frame.
7. Turn the cam lever to lock into the retention
frame.
8. Attach the four-pin power plug from the
heatsink and fan assembly to the CPU FAN
connector.
For detailed information on how to install your
heatsink and fan assembly, please refer to the
instruction manual came packed with the
heatsink and fan assembly you bought.
User's Manual