Step 1: Sign in to your online account at mynrma.com.au/login - if you haven't signed in before, you'll have to register for an online account.
Step 2: Once you're signed in, click on "Update" found next to your existing card details.
Step 3: Fill in your new card details including; name on card, card number, expiry and CVV, then click "Save".
Step 4: Your new card should now display under "Payment method" and will be charged in your next billing cycle.