I don't know about any patch available now, but BES 5.x.x still needs it's own server and can't be installed on the same one as BES 10.
I heard something about an upgrade that would allow both to be installed on the same server but that was supposed to be out around May 2013. I haven't heard anything else.
You may want to hit the BlackBerry Support Forums
General Support Forums - BlackBerry Support Community Forums