1.Download and install SoundDownloader
2.Laungh SoundDownloader
3.Open www.youtube.com website.
4.Copy the video's link and paste to editbox of SoundDownloader

5.Click the "Download" button and SoundDownloader start to download the link.
6.After the download finished, SoundDownloader will extract mp3 audio from downloaded file.

7.After extracting mp3 audio, SoundDownloader show a prompt window, you can select "Yes" to open the folder saving the downloaded files.

