I no longer have an account with Comcast and only use their email. When I go to settings in email, I don't see username and password which is where I think I need to go to turn off two factor authentication.
Here are the instructions for removing two-step verification (two factor auth)
Manage Your Two-Step Verification Contact Information
You can change or remove the mobile phone number and email address associated with Two-Step Verification at any time by following the steps below:
Note: Removing your email address or mobile phone number will automatically turn off Two-Step Verification, as we will no longer have a way to contact you to receive the verification code. If you change your email address or mobile phone number, don't forget to turn Two-Step Verification back on in the Settings section of My Account.