Bill,

It's an easy task using your keyboard. Just fire up the midi file, then press the mixing console button several times until you see the midi channels (1-8)(9-16).

Next, select digital recording, song creator, then tab to channels, press the mixing console button while the midi file is playing and note the flashing dots at the bottom of the screen. Adjust the volume of the channel(s) you wish to mute down to "0", press Execute and Save. As Joe said, save them to another name so you do not overwrite the original.

Gary