First read: What is Archive?
To archive a classroom, follow these steps:
Go to the My Classrooms list.
Choose the classroom you want to archive and click on the ARCHIVE button.
3. Please note: Archiving a classroom will not free up student seats (unless you have a Flex subscription).
4. You will get a message that your classroom was successfully archived.
How to restore archived classrooms?
How do I Archive Student Accounts?