I am probably wrong but to convert something like that you need to read it onto the correct old apple machine then read it back off of that machine, seeing as there are no current or even close to current world processing programs available for that computer it seems closer to impossible. Even things like the Sony "floppy" from the Macintosh and Lisa's you'd have a tiny bit better shot, but not much at all.
It does make you wonder what's on there though
Edit: Sent word to a friend, his day job is converting old old old film to digital, he has a lot of random old computers and things that he has up and running, I'll see if he has anything that will help.
A