Everything about your membership is on one page: open the button with your name at the top right and choose My membership.
Turn off renewal. Press Turn off renewal beside your membership and confirm. Your membership stays until the end of the year you paid for, then ends. Nothing more is charged. Until it ends, Turn renewal on puts it back.
Remove a card. Press Remove beside the card. You can remove a card at any time. If it is your only card and your membership renews, removing it also turns off renewal; the page says so, with the date your membership runs to, before you confirm.
Add or change a card. Press Add a card, enter the new card and press Save card. The new card is the one charged at renewal. With more than one card on file, Use for renewal chooses which card is charged.
Billing address. Press Change under Billing address.
Invoices. Every payment is listed at the bottom of the page with View and Download.