Blog entries are simply pages in the document tree in MODx. User Comments for an article are also stored as a child page of the original article, with special formatting. If you cannot see any child docs for an entry that contains commments, edit the post from inside the manager and turn the post into a folder. You should then see the user comments doc inside the folder. Edit that document as you would any other document, looking for the specific post you want to edit. User comments are formatted as in the following example: