The Easy YouTube mp3 Add-on includes a Button on any YouTube Page and allows you to convert the YouTube Video to a mp3 with just one click.
To use the Easy YouTube mp3 Add-on for your Browser you need to install first a user script manager. Which user script manager you can use depends on which browser you use.
After a user script manager is installed, click here to install Easy YouTube mp3 to your browser.
Visit https://www.youtube.com/new to check and update your YouTube Layout.
Visit YouTube, press the red download button below the video and download the converted mp3.