Hi Ro,
There is no tutorial for Firefeed. It's intended to be an example for you to draw ideas and code samples from for your own projects. It assumes you have a fair understanding of how web apps are built and have at least run through the basics of Firebase.
It's certainly possible to download and run it on your own machine or web server. It's a client-side app, so there is not any real installation process. You just put the files into a web server and run them.
The only setup would involve digesting the README and tweaking the js/ files. For example, there is a URL in firebase-ui.js that you'd want to point to your own Firebase instance.
Cheers,
Kato