There was a bit of photoshop trickery for this one. Basically you create a duplicate layer and desaturate it. Then you add yellow to the highlights and red to the shadows almost as though you're creating a seperate sepia version. After that you just set the layer style to hue.
It doesn't work with every shot as it depends on how many different colors there are and the level of saturation but you can get some great effects if you play about with it.