To remove access to a teacher's grade book temporarily
  1. Navigate to Core > User/Access > Profile
  2. Select Manage Roles
  3. Select the Teacher role
  4. Select Tasks under the Role Section
  5. Navigate to Manage Grade Books
  6. Select the Edit button across from Copy Grade Book and View Grade Book
  7. Unmark the check boxes for both sections.User-added image
  8. Save & Close
  9. This will remove the access temporarily for teachers to see their Grade Books which include course rosters.