I am trying to understand what it is you are trying to do ... are the vocals embedded in an audio track along with other instruments? If so, I don't know any way to remove them - you might be able make them less prominent using eq (lowering the level of the frequencies where the vocals are prominent. There is "karaoke" software that supposedly removes vocals - but it often works by identifying a signal that is identical on both left and right channels and removing it - that works when the vocal was the only thing put exactly in the center of the mix.
If the vocal is on its own separate track, it should be a simple matter to select it, and delete it.
Sorry I can't be more helpful.
