To remove the power supply unit, unlatch and remove the base cover. Unlatch and remove the front bezel. Identify and slide the tab to unlatch the hard drive assembly. Disconnect the cables and lift the assembly to remove it. Identify the power supply unit and disconnect the two cables. Remove the 3 screws and unlatch the unit to remove it from the system.
To reinstall the power supply unit, place it back in the system and relatch it. Tighten the 3 screws and reconnect the cables. Reinsert the hard drive assembly and reconnect the cables. Relatch the assembly. Place the front bezel and base cover on the system.