You can change the payment and shipping details for individual products you subscribe to, or all of your subscriptions.

Log into your account and select "My Subscriptions." Select the subscription you’d like to change payment or shipping details for and click "Payment & Shipping." Here, you’ll see your shipping, billing, and payment information associated with this subscription. Click “Change” on the information you’d like to update. Edit your information, and select whether you’d like to apply it to an individual product, or all products you subscribe to. Click "Use this Address" or "Use this Payment" to apply your new information.