Change credit card

This support article contains the details and the steps are outline both below and in the article.

If you need to change or update your Apple ID payment method - Apple Support

Update your payment method on your iPhone or iPad

1. Open the Settings app.
2. Tap your name.
3. Tap Payment & Shipping. You might be asked to sign in with your Apple ID.
4. Tap Add Payment Method, enter the new payment method, then tap Done.
5. Tap Edit.
6. Tap the red delete button next to the old payment method, then tap Delete.

apple id account

Apple has multiple accounts these days, Apple Card MasterCard, Apple ID/iCloud account (includes gift cards) and the new Apple high yield Savings account. Which account are you wanting to change?