How do I delete a discussion in a course?
You can delete a discussion or graded discussion at any time.
Note: When Multiple Grading Periods are enabled in a course, graded discussions are not currently validated against closed grading periods. Deleting a graded discussion may affect the total grade for students in your course.
In Course Navigation, click the Discussions link. There are two ways to delete a discussion topic.
Delete Discussion Topic from Discussions Index Page
Click the Settings icon next to the discussion you want to delete. Click the Delete link.
Click the title of the discussion.
Click the Settings icon to open the drop-down menu. Click the Delete link.
Click the OK button to delete the discussion.