It's rare that you can get a version that takes out _one_ instrument of a song, without it being drastically remixed (i.e. sounds quite different overall). But, if you're skilled with software on your PC to handle audio files, there's one trick used to remove an instrument which is "centered" in a mix (i.e. plays out at equal volume from both the left and right channels/speakers). The only drawback is that lead vocals are usually equally loud in both speakers. Hopefully, in this case, they are not.
1) Open your track in a audio program (I use Wavelab, but that costs money... any software that allows you to treat each channel separately will do just fine... How do you know if it treats each channel separately? It will usually show two waveforms for a stereo mix, one for the left channel, one for the right).
2) Select an entire channel (left or right). This can usually be done by bringing your cursor on the wavefile, but away from the center (i.e. in the middle of the two channels). Usually, the far top of the window for the soundfile is the left channel, the far bottom is the right channel.
(The following goes for most software run on Windows computers:)
3) Once that entire channel is selected, go to your "Help" menu, and choose "Help Topics". In the Help window that appears, click on the "Search" tab near the upper left of that window, then type in "invert audio" and press the Enter button. You should get a menu item that ressembles "invert audio". (NOTE: "Inverting" and "Reversing" are not the same when it comes to audio. You want to _invert_ the audio, a process for which description would be way too technical for this answer right now.)
4) Follow the instructions on how to invert that selected channel. (NOTE: Only invert _one_ channel or the trick won't work.)
5) Repeat Step 3 and 4, except this time search for "convert to mono" and follow the directions that appear.
You will now have a mono track that no longer plays all sounds that are equal between speakers. You have "inverted" one channel (in short, every time your speaker would "push" air out, it is now "pulling" air in), and combined it with the other channel. If one stereo channel "pushed" a sound equally while the other "pulled" it, the mono mix combines the two and you end up with that sound completely disappeared.