Via Settings > Forms
Under the Settings > Forms tab, you can switch the status to Disabled from Enabled and this will archive your form.
Archiving will de-activate your form – hiding it from public view – while retaining all submissions.
You can scroll down and click on "View Disabled Forms" to view a list of forms that have been disabled. You can then scroll down and click "Enable" for any form that you wish to re-enable.