Press the "Song" button on the piano, and then look at your screen. A list of songs should pop up, including several that say "User Song" followed by a number.
Use the scroller to move through the songs until you land on one of the "User Songs". Press "Exit" when you have your User Song highlighted.
Choose the instrument you want by pressing "Voice" and then scrolling through the list of options. Highlight the voice you want to use, then press "Exit".
Hold down the "Rec" button while simultaneously holding down the track number you want to lay down. To record piano on track three for instance, you would hold "Rec" and "3" at the same time for about one second until the "Start/Stop" button flashes red and green.
Begin playing, and the piano will automatically record as soon as you play your first note. Finalize the track by pressing "Start/Stop" when you're finished. Repeat Steps 2 through 4, only press a different number while holding "Rec" to lay down multiple tracks.
Press any number while playing the track to mute that track during playback. Delete tracks permanently one at a time by holding "Clear" and the number of the track you wish to delete. Delete the entire song by holding "Clear" and "1".