You can easily delete unwanted classes. 

  1. Go to "Classes" under "School" in the left navigation menu.
  2. Check the class you want to delete. 
  3. Choose Delete in the Actions dropdown menu. 
  4. Click "Apply"

** Please note that deleting classes may delete all of the students associated with that class, and their progress in that class. You'll have to add them again to a new class.