uncheckout document Method
SharePoint 2010
Published: May 2010
Undoes a check-out of a file from a source control database. If the file has changed after it was checked out, this method causes those changes to be lost.
method=uncheckout document:server_extension_version &service_name=/ &document_name=service_relative_path/file_name &time_checked_out=time&rlsshortterm=(true|false)