Can someone help me in removing vocals from a track and just getting the instrumental? I have watched a few YouTube videos on it and downloaded Audacity and tried it but it just sounds like crackling noise with the vocals still 40% there.

This kind of thing is very difficult to do and 90% of the time won't work well enough to be worth the effort. What is the track that you are working on?

http://youtu.be/uB6Zn9tSyOo

Here's a pretty good example of what im talking about. You can kiiiinda hear the instrumental, but whenever you can't still faintly hear the vocals, the instrumental sounds cloudy and, well, filtered.

I've tried doing this to the stutter in MTN but I failed miserably

Well I was working on Nicole Scherzinger's "Electric Blue" and I failed so badly

But MTN's official instrumental and acapella are both available online...

What everyone else said.

It's not an easy thing to do without having the stems.

I would absolutely love to have the acapella to "On a Night Like This" by Kylie but I'm not able to find it anywhere! I would love to hear an Aphrodite Les Folies Studio Version >.>

Sadly most of the time you can't get the instrumental from a song I've done it before tho to one song but it wasn't in audacity. You can only remove the music and get the acapella