How to install SilvaDocument

  If you have SilvaDocument installed in the Products directory, any
  new Silva root that is placed will automatically have SilvaDocument
  registered for it.
  
  If you want to install this into an existing Silva root, go to 
  service_extensions in the Silva root using the Zope Management Interfaces
  (services tab) and press the 'install' button for SilvaDocument.