If your current credit card is currently linked to a direct debit please follow steps below, if not, please follow Step 3 only.
Step 1: Log in to My Account
Step 2: Cancel any direct debits currently using the card you wish to remove/update.
Manage Account > Billing and Payments > Direct Debit > Manage
Step 3: Add new card in My Wallet
Manage Account > Billing and Payments > My Wallet > Add
Delete old card
Add a Payment Method
Step 4: Set up Direct Debit with your new card details
Manage Account>Billing and Payments>Direct Debit> Manage