Salvaging Apple IIe Documents

["TopCat" <Len-K@compuserve.com>]

A good friend of mine owns an Apple IIe and has several disks worth of
letters and papers that he would like to transfer to either Mac or PC
formatted disks.  I tried connecting the Apple external 3.5" drive chained
to the 5.25" to the IIe and then to the IIGS I got at a yard sale, but the
system software we have (Applewriter and Appleworks ) is apparently too old
to support 3.5" drives. I tried plugging the 5.25 " drive into a Mac
Classic running Apple Exchange but it cannot communicate with that drive. 
Is there a solution, either hardware or software one.
Thanks in advance!
Len

I've heard something about a software package called MUGI (?). Could
someone tell me where I could find it?