John ...Not sure where you are experiencing a problem, but when you press the 'SONG PLAY' or 'SEQUENCER' button on the kb, the files on the 'KORG DISK' should show on the screen ... If you want to EDIT a midi file, press 'SEQUENCER', the files should show on the screen ... scroll to the file you want to edit, press select and you should then have the file in the SEQUENCER, edit away ...
Hope this helps ... If not let me know ...