Once an assignment is created, you may decide you no longer need it. You can easily delete the assignment so it no longer shows up on your Instruction tab.
From the Create Tab > Instruction > My Created Instruction section:
Click the options icon next to the name of an assignment and click Delete.
The assignment will be removed from your Instruction tab.
Note: If this assignment has been assigned to students, they will still have access to complete the assignment. Deleting the assignment here only deletes it from your list of created instruction available to assign to your students.