change vnc listening port from 5900 to other?

In macOS versions prior to Sierra, it was possible to change the VNC (screen sharing) port from the default 5900 to something else by editing the file /System/Library/LaunchDaemons/com.apple.screensharing.plist. However, macOS Sierra disallows changing this file, even when running via sudo in Terminal.app.

I have reasons for not wanting to use this well-known port. Do I need to disable SIP prior to changing it, or can I accomplish the same thing by editing the /etc/services file, and changing the TCP/UDP ports for the rfb service?

What's the best way to change this port under Sierra?