You can leave a course by navigating to the course's dashboard and clicking Leave Course, which is located on the right-hand sidebar.
You must confirm that you want to leave the course by clicking Leave again.
After leaving a course, the course name will disappear from under Current Courses and you will no longer receive email notifications related to the course.
NOTE: This option is disabled in most courses. In that scenario students would need to contact their instructor and request to leave the course. The instructor will then remove the student from the course. Leaving a course will delete all associated coursework permanently.