Hi Jamie,
Switch ignition on and then hold the 'close' button on the fob down for a few seconds, the central locking will cycle twice.
(If it dont work with the close button repeat with the 'open' button, been a few years)
This is then sync'd.
Note if this is a new fob then you will need to go to Vx for them to sync it to the car using Tech 2
Regards
Les
Les Jones, November 2007