[Putter]

I can tell you how I did mine, and your picture that shows the bulk-head connector looks like mine as far as I can tell. I removed the small bolt that is in the center of that connector (engine side of firewall). As you unscrew it, it will disconnect itself. Locate that white wire on the connector (you might want to mark the location with some nail polish or liquid paper for later reference). Then look on the other side of it (the side that used to make connection) and find the metal connector that goes with that white wire. You can use a small flat screwdriver to press the tab of that connector sideways and release it. The wire will pull out of the connector. You can them then remove the wire from the metal connector and replace it with a new wire. After that, simply slide the connector back into the bulk-head connector (make sure it clips in properly and that it is in the right spot.....refer to nail polish) and reconnect the entire bulk-head to the firewall. All done.

Here is my quick rendering of that metal connector. You have to push that tab sideways to get it to remove. Hope that helps.