Does anyone know how to remove vocals from songs?
Don’t expect perfect results, because you’re probably working with consumer-end versions of the songs – i.e. you probably don’t have the sound engineers’ versions, which have separate tracks and are, therefore, much easier to work with. Anyway: this article at EthanWiner.com explains what you can try to do, and also why creating your very-own karaoke tracks doesn’t always work very well. Another good source is this YouTube video, in which someone uses Audacity to show you how to make an attempt at creating a karaoke version of a recorded song.