You are able to delete any debit and credit cards you have stored within your account very easily. All you need to do is navigate to your account and click 'Credit Cards' in the left hand menu. From this page you will see any stored cards on your account and can delete them simply by pressing the bin symbol next to the card.
To add a new card you would need to place an order with the card and this will then be stored to your account. Please be advised that your card details are not actually stored in the Hungrily system, we only receive a token from our payment processor Stripe which shows the last 4 digits of the card to make it identifiable to you when ordering.
Your card details are totally safe at all times.