Removing voice from MP3 files is possible with audio file editors. It is highly recommended to use a WAV file as source because WAV files are uncompressed and offer a wide spectrum of frequency, but it will work with MP3 files also. In simple terms, the success of removal is increased if you use a WAV or AIFF files.
On the other side, you can use Audacity because it's free software and it has a built-in feature for voice removal. You can access it after you install the software and it is found in the main menu of the software under Effects option.
The process of removing the vocals is done automatically: select the Remove Vocals option, click OK and then let the software process the file.