what is best way to change my email address?

hello, I am trying to change the email address associated with my account in arc. I will be losing access to this email address soon.
I tried to do it through technical support, but that just took me back to the account screen. it will not let me change my email. I have put in a ticket to ARC support. "change email address" was one of the preselected categories, so I know they know it's an issue. How do I change the address?