It's FOSS - https://itsfoss.com/upgrade-ubuntu-version/
Brief: This step-by-step tutorial demonstrates how to upgrade to Ubuntu 18.04 Beta from Ubuntu 17.10.
If you are using Ubuntu 17.10 right now and are excited about the new features in Ubuntu 18.04, you may want to try it. Ubuntu 18.04 will be coming in the end of April but if you want to try it before that, you can upgrade to Ubuntu 18.04 beta today.
Upgrade from Ubuntu 17.10 to Ubuntu 18.04 Beta