You can only Delete an Assignment Type that has not been used. If it is not used you will see a red X. If it is used you will see a Padlock Icon.

In order to remove Assignment Types no longer needed they need to be inactivated. To inactivate a Assignment Type navigate to:
  1. onCampus > Settings > Assignment Types
  2. Click the Editing Pencil next to the Assignment Type you no longer want to be active
  3. Change the Active Yes to No
  4. Click Save

Users will no longer be able to add this assignment type to a new assignment, however inactivating this will not remove any Assignments already added to the Course with that Assignment Type.