Press the "Tone" button on the left hand side, and it brings up the menu for bass, treble, etc.
Second setting down on the list (touchscreen) is for balance and fader. Select this, and it brings up a picture of four car seats with a target cursor centred over it, and 4 cursor keys to the left. Either use the cursor keys to move to target on the seat pictorial, or use the target itself. Touch screen control.
Edit: Pinched a pic from google....