How can I unquarantine documents?

Only Admin users can Unquarantine documents.  Just select one document or multiple documents, right click and select  Security >"Unquarantine". 

Once the document is unquarantined, it will no longer display the "Quarantined" label in Permissions column and will be removed from "Quarantined" Folder.  

Quarantined documents which are in Recycle Bin cannot be unquarantined.