First you will need the vehicle registration document and a Utility bill with your name on it and the same address of course.
Take the car to a local garage that has facility for re-coding.
They will do the rest it requires removal of the radio to accesss the code they need to put in the computer system. Don't remove the radio and take that down only they won't re-code it suspecting it might be a stolen radio.
Bob, June 2009