How to I change the email?

If you are referring to the email in your account, please go to My Account section on this link: https://jotform.com/myaccount/. 

Change the email by clicking on the "Edit" button as shown below.

If you are referring to the email where you receive your email notifications then this guide will help you: http://www.jotform.com/help/314-How-to-properly-Change-and-Test-a-New-Email-Recipient-Address-.