Can't change my family payment method?

I have tried everything in the Apple Support link about how to change the Shared Family Payment method on iCloud. I have tried it on my phone, on my iMac, and through the web. It lists two cards, one is the primary and one is an additional card. The primary card has expired and I want the additional card to become the primary card but there's no way to do this. There's no way to edit the primary card, to reassign the additional card, even to delete the primary card. I am the family organizer. How do I change the card?