be aware that you should test it on a virtual environment first since some services are vital for the server , for example if you turn off httpd* services you could have some noises when you will want to establish it again.
Indeed you have to do it trough the server-manager.
at least all i have tested
-what you turn off, stay off after the next reboot
-you can change port of some services
-you can change service access (public/private)
i worked on this contrib because i know that some of us have virtualized or hosted SME Server in the cloud and they do not need some services (samba, printer...)
But a big thank to Xavier who gave me the idea to work on this contrib.