haha let me guide you

http://www.youtube.com/watch?v=U-IAv8oTTQ0

then use

http://www.mediaconverter.org/

click "enter a link" and put in the youtube url. then click "go to next step"

chose "mp3" and then "ok" then "start"

once done, below you will see "download"

all should be sweet as candy after that