Based on this article
ALL INSTALLATIONS ASSUME YES WHEN PROMPTED, that's what -y does
This script can be copy paste to ssh as is. No hands installation. :-)
yum install zsh -y
chsh -s /bin/zsh root
echo $SHELL
yum install wget git -y
wget https://github.com/robbyrussell/oh-my-zsh/raw/master/tools/install.sh -O - | zsh
/bin/cp ~/.oh-my-zsh/templates/zshrc.zsh-template ~/.zshrc
source ~/.zshrc
If anyone wants ready data for ubuntu, it is here