To archive an expired membership package, head over to the Membership module in the admin area. It is recommended to archive your package after the expiry date + any grace period given on that package. This will give your members time to pay for their renewal and remain an 'active' member in the system.
Your membership packages will be grouped by "Fixed Date" and "Date of Purchase" memberships. The process will be the same for both groups.
Click on the blue "Options" button to the right of the membership you wish to archive, select the option "Make archived":
After the onscreen confirmation - you will see that the package is now showing on your list with the Availability "Unavailable". This package has been archived.
You can view 'Active' and 'Archived' packages by selecting one of the options.