Does anybody know how to remove the door cards from a 97 A4 TDI?

I have some new speakers to fit but cant see any obvious way of accessing screws etc. I would normally just take everything off that I can get a screwdriver behind but its not my car and I dont want to damage anything.

Thanks in advance

Karl
[img]/ubbthreads/images/graemlins/smile.gif[/img]