1. Installation

You can install this software by going to their Github page or Website and download it for your environment. It is quite straight forward and simple to install. Especially if you are running debian on your machine then you can just download the .deb file ;) 

Once, installed you simply select the file you want to compress -> choose the qualities you want to keep -> then simply hit compress and it all happens on the background for you.

For more information on details I would simply refer to their documentation page. 

Cheers!!