You update an external blog post to synchronize it with
  the version in the site blog.
    This task assumes you are in the blog of the desired
    site.
    Updating an internal post without updating the external post at
    the same time results in the internal post being marked as Out
    of sync. This status in the site blog is a visual indicator to
    remind you that the internal and external blogs are displaying two
    different versions of the post.
    - 
        Browse the blog posts to locate the external post you want to
        update.
        Fastpath: Select the Published Externally filter in the browsing pane to display only the externally published posts.
 - 
        Click Update Externally to synchronize the
        externally published post with the version in the site blog.
        
Optionally, open the post to perform this action.
 
A message indicates the external post has been updated. The status
    Out of sync is replaced with the status
    Published.