You can learn from this article how to change the email you use to log in to your GoToMyPC account.

1. Log in at https://www.GoToMyPC.com/members/login.tmpl.
2. Click My Account in the left toolbar.
3. Type in your new email address and enter your current password where required.
4. Click Save Changes.
5. You'll receive instructions in your inbox of the new email address you used.
6. Open the email and click on the link to finish changing the account email address