Now you should see a cord running around the outside of the fan with two red wires and two black wires, this is the dc jack wires.

Unplug this connector, gently.

Now flip the computer over and pop off the panel containing the speaker grille. There are multiple clips along its length. I just stuck my fingernail under its left edge next to the dc jack's chrome trim and pried it up gently and worked my way across until it completely popped off.

Remember these are small plastic clips so go slowly and cautiously.

Now you should see the other side of that dc jack wire coming up through a hole and going to (where else) the dc jack.

Remove the one screw on top and pull the metal cover off.

This part is tricky. Pull back on the jack and up at the same time so it pulls out of the hole. It takes a little work just be careful not to break the nice shiny chrome trim. Using needle nose pliers around the plastic body of the jack may help.