Open the belly door, open the main door, Raise the deck by pulling the yellow handle on the interior left cabinet wall and push the deck upward to the raised position. You will now have access to the power supply. With your hand, carefully reach back on the top rear area of the power supply near the backplane and feel around for the thumb screw. Turn the thumb screw counterclockwise until it disengages, then using the handle on the front of power supply, firmly pull the power supply out unplugging it from the backplane then lift it out.