1. Navigate to Core > User/Access > Profile
  2. Select Withdraw Employees
  3. Select an employee name from the list
  4. Select Next
  5. Enter an Effective Date/Time or select the radio button for Immediately and Remove Access if needed
  6. Save & Exit
Note: You will also need to remove the Teacher from their Courses and or Groups unless you disable their login credentials, or they will still have access to them.