Open Audacity and load any song file from your hard drive. Click the "File" menu on your menu bar, select "Import," and then select "Audio" from the second drop-down menu. Use the navigation window to select the desired song file from your hard drive.
Click "Effect" on the menu bar, scroll down near the bottom of the list and select "Vocal Remover." A new pop-up window will appear. Select "Remove Vocals" on the first pop-up menu and "Simple" on the second pop-up menu. Note that this feature removes all center-panned audio, so you may lose some of your bass quality as well.
Press the green "Play" button on your Audacity window. If you feel satisfied with the results, you can move on and save your results. If the entire sound file now has poor quality, click (Edit > Undo) on your menu bar to undo the change. Then select (Effect > Vocal Remover) a second time, and choose "Retain Frequency Band" on the "Removal Choice" submenu.
Click (File > Export) on your menu bar. On the navigation window, enter the name of the song and choose a destination format, such as "WAV," "AIFF," or "MP3." Click "Save" in the lower right corner.