It's an unwritten rule that the white wire will work as common series. Stick by this rule to prevent confusion by others concentrating on your circle. It's called common simply because it is come with all valves. The white wire is hooked almost the large bundle of solenoid cables that. For example, if the four valves there are usually four solenoid wires just one white common wire all hooked together with a wire connector.
Then a few additional remove the hard drive. Normally you discover four screws holding it in. Two on each side, Shielded Cable positive if you most likely not requirement to remove another panel to obtain the screws on lack of. The cage that the hard drive is in is probably kept in by one screw using a spring attach. Undo that screw and push in the clip latch toward the cage and pull the cage free.