To change your bank account associated with your Stripe account, please log in to your Stripe.com account and head over to the Stripe payout settings page at https://dashboard.stripe.com/payouts/overview.
You should see your default deposit bank listed. Click Edit on the bank. A new window will appear and allow you to enter the new bank account number.
For PayPal donations, you will need to login to your PayPal account > Account Settings > Money, banks and cards. Here, you can edit or link a new bank accordingly.