DJ Twist & Burn has a built in vocal remover! Right click on a song and select "Vocal Remover 1", "Vocal Remover 2" or "Vocal Remover 3".
If you want to fine tune the vocal removal, click "Adjust Song Volume/Boost/Effects" from the "Song List" menu and then click "Customize". Click on "Vocal Removal" and adjust the various parameters.
Remember, vocal removal is not an exact science and will vary in quality from song to song!