You'll need to have a current subscription, in good standing in order to view it or make changes.
Login to your account using your subscription email.
Click on the "Manage your Subscription" link in the footer, or click on My Account at the very top of the page.
If you clicked on "My account" you'll be brought to your account page. Click on "Manage Subscription" Under My Subscriptions on your account page. If not, go directly to Step 4.
On the next page, click on the blue "manage" link next to the subscription you want to manage.
From that drop down menu, you can edit your credit card, shipping address, pause months, and more.