5.From the rear of the computer, remove the four screws that secure the power supply to the computer.
6.On the inside of the computer, press the tab at the front of the power supply (1), pull the power supply forward, slide it back and toward the side of the computer so it can sit lower on the bottom of the computer, and then rotate it and lift it out of the computer (2).
To install the power supply, reverse the removal procedure.
CAUTION: When installing the power supply cables, make sure they are properly positioned so they are not cut by the drive cage and are not pinched by the rotating power supply.
Power Supply 139