I followed the instructions from here except for the 3rd step (the configuration of environmental variables) which I took care of in my local .bashrc script.

cd /opt/
sudo wget http://mirrors.advancedhosters.com/apache/tomcat/tomcat-9/v9.0.0.M13/bin/apache-tomcat-9.0.0.M13.tar.gz
sudo tar xvfz apache-tomcat-9.0.0.M13.tar.gz
sudo ln -s apache-tomcat-9.0.0.M13 tomcat9

Also, to be able to deploy content I did the following:

cd /opt/tomcat9
sudo chown -R mperdikeas:mperdikeas .