After logging in to your BSCpro account, you can modify you payment settings by click on the down arrow at the top right of the page next to your name. You should see an option in the pulldown for Profile. From the profile page, you should see some tabs like the image below. Click the "Payment Settings" tab.
Next, simply click the blue "Change" button to change your credit card on file. Unless you have a pending payment, you will not receive any charges. When your renewal date arrives, this new card will be charged instead of the old payment method.