The relevant fuse box is the one behind the passenger glovebox (there is another one under the bonnet).
I have a Ford Modeo 1.6 V (M-reg) and here is what to do:
You first need to remove the glovebox. The fuse box appears once the glovebox is taken away.
Once the glove box has been removed, you will see the fuses inside the fuse box, but you won't be able to remove and replace them yet: you need to lower the fuse box first.
To do this, use the lever on the right of the fuse box, and lower it slowly.
You can now replace the fuse.
I don't know which fuse corresponds to the cigar lighter though. I am myself looking for this information...
Raphael
April 2009