Payment partners such as PayPal or eBay unfortunately only accept a change of bank account via the online portal of your respective payment partner.
Also here we have thought along and send you, with the first e-mail already the link to the respective portal.
Quite simply:
Login
Enter new bank details
Save
Of course, you will also receive an overview of the online partners found in your transfer protocol, which is sent as part of the account switch package with the second e-mail.