I'm not familiar with the Mac OS, but in Windows, you'd use something like:
Code:
Dim StrNm As String: StrNm = ActiveDocument.Fullname
ActiveDocument.SaveAs FileName:= "/Users/hl/Downloads/FileName.docx", FileFormat:=wdFormatXMLDocument, AddToRecentFiles:=False
ActiveDocument.Close
Kill StrNm
Application.Quit