To remove the hard drive, remove the 6 screws securing the base cover and the 2 screws by the hinges. Pry the cover off the recess points near the hinges. Identify the hard drive assembly and unplug the cables.
Remove the 4 screws and lift the assembly out of the system. Disconnect the hard drive cables and remove the 4 screws to remove the drive from the assembly. To reinstall the hard drive, place it back in the assembly and tighten the 4 screws.
Reconnect the hard drive cables. Place the assembly back in the system and install the 4 screws. Reconnect the cables. Place the base cover back on the system and secure it with the screws.