I installed modeller on Macbook Pro OS X Yosemite 10.10.5. But it does
not work. I made the python files and transferred them to the bin folder
in library.
The /Library directory on your Mac is for system tools - you should not
put your own files there or change anything in that directory. This is
why you are getting a "permission denied" error. Put your Modeller
scripts in a folder under your home directory or on your desktop, and
then run them exactly as you have been doing.