I have multiple computers in my house and like to change the VNC listening ports on each to unique numbers as an added layer of protection.
In the past, when changing the VNC listening port on my two Macs, I've followed the following prior article:
http://superuser.com/questions/148095/how-to-change-the-default-screen-sharing-vnc-port-number-on-mac-os-x
However, when I tried to following this article (after upgrading to El Capitan), SUDO will not permit me to Write / Save the file after making the requisite changes. It just says "ERROR WRITING".
I never had this problem before with Mountain Lion or Yosemite.
Your suggestions are greatly appreciate (please note that I am only a novice so please provide step by step instructions).
Thanks!