To archive a space in your Accompa system:

• Login to Accompa using an account that has 'Administrator' privileges.
• Click Settings on the top-right, and select Customize Accompa from the menu.
• Click  Manage spaces link under "Manage Spaces" section.
• In the resulting page, click actions next to the space you'd like to edit.
• In the menu that appears, select Archive Space and follow on-screen instructions.

Here's a video with the steps to archive a space: