Go to Assignments.
Select the Assignments tool from the Tool Menu of your site.
Select the assignment(s) you want to delete.
In the "Remove?" column, click to place a check in the box for the item(s) you want to delete.
Click Remove Selected.
Click the Remove Selected button at the bottom of the assignment listing.
Confirm the deletion.
Click the Delete button to confirm the removal of the assignment(s) you have selected.
Note: Removing an assignment with student submissions will also delete the submissions for that assignment.