You want to change the contact's e-mail from a course.
Learning Management System Core
Reproducing the Issue
Logged as a user on LMS, open a course to check the contact's e-mail, as showed on the screenshot below.
Navigate to the course record and find the field Contact's E-mail and change it:
Contact's e-mail Changing course e-mail Course contact , KBA , LOD-SF-LMS-COR , LMS Core - Items, Catalog, Curricula , How To