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 Gradebooks
  6. Select the Edit button across from Copy Gradebook and View Gradebook
  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 Gradebooks which include course rosters.