On the Control Panel, expand the Users and Groups section and click Users.
Select Find Users to Enroll.
Type a username or click Browse to search for users. Only users that are not already enrolled in your course will be identified in a search for users.
Select a Role based on what the person is will be doing inside your course and leave Enrollment Availability set to yes so they can access your course.
This is not a permanent add. To get the user on your roster permanently contact Registrar.