You manage your details and account information under the Account icon > Profile > Account Details.
You will find your billing details and stored payment methods under Billing Details.
Edit Billing details
To edit your billing information select Billing details > Edit.
Payment methods
Add/Remove card
To add a debit och credit card select Billing details > + Add card.
To remove a card, click the Trash icon.
Removing a card is permanent and cannot be undone.