Changing your bank account is very easy.  Download this form, fill in the information and fax the form with a voided check or bank letter to 1-888-209-4888.  If you have any questions please call customer service at 1-800-935-5961.
Please included a voided check with your fax or a bank letter on bank letterhead that states your account number and routing number.
Note: You may also perform this change using your mxmerchant account under account/merchant services/bank accounts.