First step was to make the cord. I used the 12v cigarette lighter plug and wire from an old auto vacuum dust-buster like thing. You could find the same on one of those cheep little air compressors or just about anything that runs off the cigarette lighter.
I attached a power plug from another device that I happen to have lying around. You can just as easily get one from Radio Shack for a few bucks. Be sure to connect the center connector of the cigarette lighter plug to the center post of the female power connector.