Please contact support@esportsea.com via the email address attached to your ESEA account. There you will be required to provide proof of ownership of the Steam account attached to the ESEA account as well as evidence of previous purchases of ESEA if you previously paid for membership.
Please note the removal of an MFA device will take several days where the contact information associated with the ESEA account will be repeatedly contacted letting them know that a removal request has been made. This is required as a security precaution to allow an account owner to dispute the process.