Paste the URL of the YouTube video into the box labeled "From URL," which is found in the middle of the Video page.
Select "MP3 (.mp3)" in the scroll box below the "From URL" box.
Click the box labeled "Convert/Download" and your video will begin converting to mp3 format. This may take a few minutes depending on your connection speed and the size of the video.
Right-click on the link for the newly created audio file, which is found underneath the "Video Conversion is Done Successfully!!!" heading. The file should begin with the word "videos" and end with ".mp3."
Once you right-click on the link, you will probably want to rename the file to match the name of the song.
Save the file to whichever folder you use to store your audio files and your download will be complete.