TL;DR
1 week before your license expires, you're reminded about the renewal by email. That email contains a link to manually renew your license, which allows you to use a different payment method or credit card.
Full Answer
If your card is expired or cancelled, or you deleted your PayPal account, you might want to change your payment method for the automatic renewal of your license.
Although it is quite common to store your credit card information (which would allow for you to change it), I don't believe in this approach.
To prevent any type of abuse/fraud in the unlikely event of a security breach, I maintain a simple method to protect your credit card information: I don't keep it at all. Neither does my payment provider; Mollie.
For the automatic renewal of your license, a PIN is generated upon payment which is shared between my payment provider and your card provider or PayPal, and strictly used to identify your card and charge it on the day your license expires.
So, to answer your question, changing your payment information/method isn't possible in the way you'd expect it to be.
However, 1 week before your license expires, you're reminded about the renewal by email. That email contains a link to manually renew your license, which allows you to use a different payment method or credit card. After your payment is processed, your new card will be used for the automatic renewal.