can any one tell how to replace headlight and main beam bulbs on a 2008 mondeo estate please? I am thinking of fitting xenons as replacement would that be a good idea do you think .

you will be better removing the headlights to fit the bulbs,there is a good guide on the fifth link here
http://www.google.co.uk/search?q=Headlight+Removal+%E2%80%93+Mk4
remember that xenons now come under the mot so you will have to have headlamp cleaners and self leveling suspension.