go to your firefox account (top right on page where your name is) then select edit profile. select "change e-mail. done.

You will have to add the new email address as a secondary email address and confirm the email address. Once this is done then you can make that secondary email address your primary email address.

• https://support.mozilla.org/en-US/kb/add-secondary-email-address-firefox-accounts
• https://support.mozilla.org/en-US/kb/change-primary-email-address-firefox-accounts

When I enter my new email address it says it already exists BUT it is not listed as my secondary to delete the old address. I've tried multiple times to get it to accept the new address but it just locks up and never completes the process.

Is that an email address you might have used in the past ?

Can you login using that new email address ?