There are tools you can buy or you can use brute strength. I think I used a screwdriver with card behind to protect the leather near the fixing plus pulling the card.. The one right at the front can be left as you can just get access.
In typical MMC fashion the passenger side was a pig, the drivers side easy
Thank you for your advice John. I will have another go using more force. You didn't mention it, so I am presuming the retaining clips or plug or whatever they are, came away with the card and were intact and reusable, rather than being sacrificial and needing a fresh fixing?