I never believe these "fixed" versions people make. You can't take a stereo recording a pump up just one instrument, it is physically impossible. You can enhance frequencies, but it will turn up everything in that frequency range.
Unless you have the original mastering tapes you can't do this. My hunch is that these merely having someone else's playing superimposed over the recording.
Unless you have the original mastering tapes you can't do this. My hunch is that these merely having someone else's playing superimposed over the recording.