You can change your linked bank account by following these steps.
1. In Messenger, tap on Menu:
2. Then tap on Profile & Settings:
3. Swipe to Bank account, then tap on Manage:
4. You will see the bank account you have currently linked, or a list of bank if you don't have any account linked. To change your account, tap 'Change account'. If your account is in error, the button will say 'Re-link account':
5. Select which account you want to link, or tap 'Link to another bank' to change banks completely.