Log in to your My Mirror account and click on Profile. This will be on the left-hand side menu if you are on a PC/Laptop or under the drop-down menu near your name on the top right-hand corner of the page if you are on a mobile device.

Scroll down to payment methods. Here you can add a new payment method by adding in your new card details and clicking “Save your payment method.” You can also select which card is your Primary method of payment.

You can always come back here to see the cards you have already added to your profile to make any updates or changes.