Disklavier

I am actually writing for a friend who just purchased a Yamaha DC II 
Disklavier and has been trying to download music samples to play on 
his piano. This is all foreign to me so if you might have any 
information as to how to do this please advise. If possible, please 
explain in the simplest manner as to the steps to take to do this. 
Are ther files on this site that he mgiht be able to download and 
play in his piano? If so, will the piano play with the music that 
was downloaded? And what type of files are they?

PLEASE HELP !

Dennis D.