i dl’d an example def from the manual, duplicated it and opened it with space bar. on top right corner it says “open with text edit”.
then i selected all and replaced with instr def from forum.
last step was rename to nameofsynth.txt (your name of synth 
)
they just have to be put in the hapax folder on card where all the projects are.
this worked for me on mac, no change of settings or whatever