From the SMS:

To un-quarantine from the All Devices quarantine tab

1. On the Devices screen, expand the All Devices in the Navigation pane.
2. Select Events from the Navigation pane.
3. Select the Quarantine Hosts tab
4. To clear all quarantines regardless of the device:
   • Click the Unquarantine All button
5. To clear a specific device quarantine:
   • Select the specific device and click the Unquarantine button

To un-quarantine from the specific device quarantine tab

1. On the Devices screen, expand the All Devices in the Navigation pane.
2. Select a device and expand the options.
3. Select the Quarantine Hosts tab
4. To clear all quarantines:
   • Click the Unquarantine All button
5. To clear a specific device quarantine:
   • Select the specific device and click the Unquarantine button