I've saved the credit card for later usage with SetupIntent to the customer. Let's say that the user wants to edit his card (expiration/cvc/billing, etc..) after 5 days.
What would be the workflow for it?
Documentation got me confused because they propose to create a new SetupIntent and attach it to the customer. If that's so, what should we do with the previously added card?
For very good privacy reasons, there's very little you can "edit" on a user's payment methods. Stripe allows an almost unlimited number of paymentMethods attached to a customer. The recommended flow (as I also answered on Discord) is to attach the new paymentMethod - you can simply delete the previous one(s). When you query the API for a customer's payment Methods (list), they are returned in reverse chronological order - the first one is the most recent.