First, click the Assignments tab in the navigation bar of your course:
You will see a list of every assignment and test/quiz in your course. To delete one, click the X icon at the end of the row for the item you wish to delete:
A confirmation window will appear:
Click Delete Item if you wish to delete the item, or click Cancel (or outside of the Delete Assignment window) to return to the Documents tab without deletion.
If there have been any submissions or grading for the assignment, you must click the confirmation checkbox before you will be able to click the Delete button.
WARNING: Notebowl does not have a Recycle Bin. Please be sure you are deleting the correct assignment.