It is impossible to remove just one instrument (in this case the human voice) from a mixed-down recording. The only way that success can be guaranteed is to have access to the individual tracks that make up the original recording, and then do your own re-mix. Yes, Audacity has an Effect called “Vocal Remover (for center-panned vocals)…” I’ve added the bold italic underscore emphasis because this effect is accurately titled but always results in a false expectation from new users. It works only on old recordings where the solo singer was placed in the dead-center of the stereo sound stage. All modern recordings apply some degree of special stereo effects to the lead singer’s voice. The presence of these effects renders it impossible to remove even an apparently center-panned voice - because some of it isn’t center-panned at all. And in any case, you will always remove everything else that is center-panned or that sits across the center of the stereo sound stage.