Take Apart Power Supply, PCI/AGP Graphics/Gigabit Ethernet/Digital Audio - 126
4. On the inside of the chassis, remove the screw that attaches the power supply to the power supply shelf.
5. Slide the power supply forward toward the front of the computer. Maneuver the power supply (clearing the security bar on the inside and upper chassis) and its cables out of the chassis.
Note: If you are replacing the power supply, remove the power supply bracket
