How can I change the primary email address on my form?

Are you referring to the form only or on the account?

If you want to change the email address on the account, please follow these steps:

1. Click the user icon and then click the "Account" text link.

2. Under Profile, click the edit button in the email.

If you wan to change the email address in the email notification, please refer to this guide: http://www.jotform.com/help/41-Finding-out-E-mail-Address-used-for-submission-notifications