Once you have sent an assignment you cannot delete or remove it. You can, however, cancel it to prevent your students from answering it!
Open your class, click on the "Assignments" tab.
Question assignments
Your assignment should be under the 'Active Assignments', click on your question assignment.
Click on the 'End now' button.
Note: If an assignment is set to accept late submissions, it will not be removed from the student’s dashboard unless completed.
Book assignments
Your assignment should be under the 'Active Assignments', click on your book assignment. Clicking a book assignment from within the assignment tab takes you to the book assignment overview page.
The “edit assignment” button in the top right of the book assignment header allows you to edit details or end the assignment.