You can try. Here's a list of free audio editors: [link]
I'm sure there are programs in existence that could disassemble it into tracks, but I doubt anything free. So it's not going to be something where you can just take a few seconds and be done with it, you'll have to play around.
Only possible if you have the original tracks separately. Else, it's not possible as the different parts are "melted" (AKA if you want to filter the voice out, wich theoritically could be possible by choosing the frequencies of the voice and wipe them out, you would also wipe out the instruments who are playing on the same frequencies, and end with a soup no longer "identifyable"). Simply consider this song track you have as a single long "sound", from which you can't pic out a specific voice.
In a sound studio, they have to record instruments separately to be able to modify their sound separately. Precisely BECAUSE it is impossible to isolate a voice after the mixdown.
Unless you find the instrumental elsewhere (DJ websites, maybe ?), I guess you will be forced to work with the complete song.
I tried to do my best to explain (and in English, it's quite tough for me when it comes to technical vocabulary ), so I hope it was clear. Else, feel free to ask