The pedal works by means of a bulb and a light dependant receiver (LDR). By pressing the pedal the LDR receives a minimum light wich results in an increase of volume. When the light is broken or has a contact issue, the organ will sound at its loudest.
To remove the pedal a screw at the front must be removed. Next pull the pedal at the bottom in your direction. The pedal can be opened by removing the bolts at the side. The bulb has the resemblance of a bicycle bulb, in this case of 24 volts.