You need to download Stellarium Scope and the ASCOM EQ5/6 drivers for it to work through Stellarium. The websites for the programs are:
http://ascom-standards.org/Downloads/Index.htm - ASCOM Platform. This is the language from your computer to your mount.
http://eq-mod.sourceforge.net/eqaindex.html EQASCOM. This is a virtual handset that will directly control your mount from a computer.
http://www.bytearts.com/stellarium/ - This talks between Stellarium and the EQASCOM interface.
All of these programs are free (Yay!) but as far as I know will only work with Windows. Hope this helps!
Cheers,
Nathan