It can be done with Eq but when you do it you cut out frequencies other parts of the mix also use and it will sound horrible there would be a big hole in your mix and there would still be nuances of the cut out vocal in there no matter what and the more frequencies you would cut the more it would fuck up the shit you were trying to keep in a 2 track stereo mix. Like someone else said on;y way it can be done is if you have access to the master and you mute the vocals out even then depending on if it was a live session or something the vocals might still be in there cuz the mics from other instruments might have picked it up still
