[Mediawiki-l] Updating mediawiki with hacked pages

[a@kid]

Is there any documentation on the best approach to updating a  
mediawiki installation where the site administrator has modified  
several of the core pages in the includes folder?

I haven't gone through an update process yet so i don't know what to  
expect. My host provides one click updates for mediawiki. I am  
wondering what the easiest way is going to be to tell which files  
have been altered in an update.

thanks