PS HarriJaakkonen :~/Blog/Posts> cat ./enable-or-disable-trace-logging-in.html

Enable or Disable Trace Logging in Dirsync and Azure AD Connect.

The following page has all is needed.
 
http://social.technet.microsoft.com/wiki/contents/articles/18103.microsoft-online-services-sign-in-assistant-how-to-enable-debug-tracing.aspx