How Do I Update My Credit Card On File?
Step 1: Log into your account;
How Do I Update My Credit Card On File - Watch Video
Step 2: From the main dashboard click on the “Account Settings” button. 
Step 3: Click on the “Update: button under “My Billing Information”.
Step 4: Update your credit card details, make sure you check the box to agree, then click on “Update Card” at the bottom.
Please note that your new billing information will be used for any recurring payments and also for any premium certificate purchases from your account.
That's it!