David Smith wrote: "I ... would like to produce some music files for the
instrument for myself.  I have Cakewalk installed on my computer ..."

Technical answer: You export the file as MIDI (I don't know Cakewalk,
but it seems there is a "Save as MIDI" option) and then copy it onto
the medium of your organ (typically an SD card).  Before that, you check
that the MIDI channel of all your Cakewalk tracks is Channel 1 (one).

But, if you want some more advice on the musical side of arranging,
you might want to read my (old) treatise, "A short course on arranging
for small organs," at http://www.haraldmmueller.de/arrco_en.html 

Regards,
Harald Mueller