It's on page 124 of the guidebook I've got (which I think is the 2007 version; and which is available from the Panda Downloads section). It's a bit complicated; and you'll need your five-digit code (which was removed from most cars, when they arrived in the UK, for spurious insurance reasons... -- hopefully this won't apply to you...). You can also obtain your code from a dealer for £30 or so....
Here goes... -- and good luck...!
