After creating an activity, you may need to edit or delete that activity. You can only edit or delete activities that you have created, or made a copy of. This applies to Custom and Performance activities only.
Any edits that you make will not be applied to activities already assigned to students. If you wish to have students complete the revised activity, you should delete the assignment and assign the newly edited activity.
You cannot delete an activity that is assigned to students. If you wish to completely delete an item, you must delete the assignment and then the activity.