check out this post from ElPres below (follow the link for the install steps) HOW TO: install MINEOS-NODE on UBUNTU SERVER 14.04.2
I may look at this in the future, I would assume that the process would be
shutdown all servers
backup all servers and copy tar.gz different directory (just in case)
sudo service mineos stop (if i remember correctly)
sudo rm /usr/games/minecraft
sudo rm /etc/init.d/mineos
sudo rm /etc/init.d/minecraft
Then follow the directions to install new one, hopefully it picks up everything and just works but in case it doesn’t you can always import the backups you made.
Be sure that you run node WebUI with sudo
sudo node webui.js