how to store midi / karaoke files externally ? (Yamaha CVP 900)

I have a Yamaha CVP 900 and many more midi files ( in floppy disks) than the internal Yamaha hard drive allows to be internally stored. It's a hassle having to insert floppies all the time to play a midi file. How can I store all my midi files externally such as on a PC and connect to the CVP 900 so I can call each of the externally stored midis/ kareoke files whenever I am on the Yamaha clavinova? I can play my PC midis/kareoke files on the clavinova through the MIDI interface but all that does is reproduce the sound of the midi file from the computer through the clavinova speakers, I dont see the "play along lights" on the clavinova or the kareoke sing along lyrics on the clavinova screen when it is playing on the PC