I have a problem with the central locking on my 2003 (L322) RR Vogue. It all works as it should apart from the driver’s door not unlocking with key fob. When the key is pressed I can hear a “clunk” noise in the door. The driver's door can be opened by inserting the key into the lock. If using the dashboard locking button, all doors lock and unlock apart from the driver's door. I think I can deal with dismantling the door myself but need to know in advance which replacement parts to buy. Your help and advice would be much appreciated please.