Users with admin rights are able to update the Course-Creator (Primary Instructor).
From the Course panel of the course in question, click on the Instructors option and select the desired Primary Instructor.
From the same page, you can also add additional instructors for your course. Just head to the Add Instructors tab and click the plus icon "+" next to the member you want to add as an instructor.
Select Save when finished.
Please note that if the primary instructor of a course is deactivated, then the Academy Admin will be set as the course's primary instructor.