Allied Telesis AT-SBx81CFC960 - Manual (Page 242)

Chapter 12: Replacing Modules
242 Section II: Installing the Chassis
Figure 161. Reinstalling the Nut and Washer on the Grounding Post
11. Lift the locking handle and slide the power supply from the chassis.
Refer to Figure 162 on page 243.
Warning
The power supply is heavy. Use both hands to hold the module as
you remove it from the chassis.