HP Elite 8300 Series Convertible Minitower Maintenance And Service Manual page 172

7. Slide the power supply toward the front of the computer (2), rotate toward the fan so the power
supply clears the lip on the top of the chassis, and then lift the power supply out of the chassis
(3).
Figure 7-35
To install the power supply, reverse the removal procedure.
160 Chapter 7 Removal and Replacement Procedures Microtower (MT) Chassis
Removing the power supply