look through the grille, and you will see the part the cord attatches to, take a flathead screwdriver, and push the latch that the cable is attatched to... very easy.. id post pics, but im not on my computer right now
I've had this happen THREE times on my focus. Only thing to do is take it in and get it replaced or attempt to do it yourself. It's a complete PISS OFF and I believe there is a TSB on this, check at the dealership.
VERY COMMON thing to happen in Canada, especially in winter.