How do I change the primary e-mail associated with our account?

Hello,

We are a small US school and are changing all the domain extension on our email accounts, migrating our website, etc., and the email account used to initially sign up for our Ring Central service will be deleted. How do I get this information changed? I have changed my contact information but messages for the main number and information about the primary account still go to the other address.

Suggestions? Solutions?

Thanks.