It is a matter of filtering out certain frequencies, this can be done with a parametric eq. Basically, you take a couple of notch filters set about -12db down and sweep the highs with one and mids with another until you kill the spots you want gone, then play with the q settings until the sound you want gone has disappeared without affecting the rest of the sample.
Play around with a parametric eq for a bit, you will figure out how to filter out almost anything.
Also, a good tool for specifically removing parts of songs without the guesswork is the Electrix Eq killer. It's a small unit that runs about $150 new and it really does what it says very well. It is also capable of a few cool tricks with midi sync and other interesting functions. The company died out a few years ago and just came back this year because of the high demand for their products. (The other products from them are great too.)
Here is their address:
http://www.electrixpro.com