Breaking down into subpages
Alison - is the best method just to create the new pages, copy over and then get rid of the old ones? Guessing there's no way just to change the page name/url
It possible to use the move feature in Mediawiki,
But in this instance I would suggest is may be easier just to create the new pages. In the first edit, acknowledging the copyright of the original contributors.
Now is a good time to make the change before history of community edits becomes a challenge.