Disconnect the trailers from the power unit, via plugs located in the ends of the trailers. This makes handling easier. The 21-MTC plug is located within the power unit. The power unit's body is removed from its chassis by splaying the lower sides outwards, and gently removing the powered chassis. The chassis has four decent sized lugs which retain the body.
Custom speakers from DCCSound are installed in the model, one in the guard's compartment of each passenger trailer. These are 8 ohm speakers, wired in parallel to match the 4 ohm impedance of the LokSound V5 decoder's sound amplifier. Each speaker is wired to the 'SPK' solder pads on the small PCB located in the end of each trailer. It is important to configure the wiring such that the speakers pump in phase with each other, otherwise the sound from one speaker can (partially) cancel out the sound energy from the other speaker if pumping 180° out of phase.
Custom speaker attached to small PCB:
Speaker installed in ceiling of body. Speaker is not visible once model is reassembled:
ESU LokSound V5 21-MTC decoder (58429) installed in power unit:
Note: Handle the 21 pin decoder with care - avoid electrostatic discharge to the decoder during handling, and ensure it is inserted correctly (refer to image of decoder mounted, as below), as incorrect insertion voids the decoder's warranty (misuse). Ensure passenger cars are reconnected in correct orientation with power unit (first class to first class), otherwise a short will occur and likely damage the decoder.