Open your audio editing software. Click "Import Audio" (or a similar option) and browse to the location of the binaural beat file on your computer. Select the file then click "OK" to import it into the software. Repeat this process to import the music you wish to mix with the binaural beats.
Adjust the volume of your binaural track down with the volume slider next to it. Press "Play" to listen to the compiled music and binaural beats. Tweak the volume level until the binaural beats are just below the level that you notice them consciously. When the volume level of the binaural beats is just below the level of conscious perception it does not interfere with the music.
Save your audio project then export it as an audio file or to audio CD. Choose to export it as an mp3 file if you want to play it on your portable music player.