Step 1 : Log-in to customer portal.
Step 2 : Go to the add-ons section and click on edit link under the Actions column.
Step 3 : Edit the Details of primary add-on and click on Submit. That will change the login details of eCC Applications.
Step 4 : Now you need change the account email so that you can login to portal with new details. Click on Home icon. It will redirect you to the account detail page.
Step 5 : Click on edit.
Step 6 : Click on edit primary email and submit it and your portal login will be updated.