Once your music is on the computer, I believe you can transfer them onto onboard memory of the Disklavier itself, or onto a USB stick from which the Disklavier can read. This way you don't need a computer to play the music on your Disklavier.
I also can copy music from Yamaha PianoSoft CD's onto the Disklavier. That way I don't need to use the CD player to play the Disklavier. The CD player in the long run will suffer the same fate as the floppy drive and might fail at any moment, I am afraid.
Minh