It is not possible to change your current credit card. So, you will have to set up a new Easy Payment method. To do so, go to “My Viking” → “Settings” → “Payment settings” → “Add Easy Payment”. Afterward, you can delete the old method.
Tip: it’s much better to do this too early, rather than too late! The approval for your new bank instructions can take up to 10 workdays to be processed.