Look ouf for audio production software with karaoke functionality. Music Maker or Music Studio by Magix contain such a tool.
If you want to do it manually, you should first use an equalizer and extract the vocals from the original material. Then, phase invert the extracted vocals and add it to the original song. The vocals will be removed then.
The less effects in the original audio material, the better the results in the end. If there is, for instance, much reverb on the vocals, there will most probably be some leftovers in the final result.
BabaSikander was partly right... first look for a product that supports it. If you already own a product then read on.
Unfortunately you can not remove vocals with an eq; once vocals are in the mix the eq will only change the frequencies. It's impossible to remove vocals with eq,
Since vocals are usually recorded in stereo right in the middle of the mix; you can make two tracks each with a copy of the song. Invert the phase on only one track and that will usually remove (cancel) most vocals. This doesn't always work and tends to leave artifacts. I think this is what Baba was trying to explain.
A third option is to search the web for vocal remover or karaoke vst plugins. There are many free ones that you can use in your Magix product.