Couldn’t figure out how to delete a post. This is no longer relevant – actual problem is detailed in the other thread.
I think this method is flawed. On the next reboot, the newly installed node is gone, yet it is still registered, which causes a mysterious failure on boot. See the harrowing tale at http://www.multitech.net/developer/forums/topic/continuous-reload-of-node-red-page/#post-16011.
So I don’t know the correct way. Maybe it’s npm install -g node-red-contrib-the-new-node
for a global install in /usr/lib/node_modules. But I can’t get node-red to run at all now despite hours battling with it, so at this stage, proceed with caution!