Items used:
ESU 58429 LokSound 5 DCC 21-MTC decoder
DCCSound Premium sugarcube speaker to suit Auscision G/BL class
To access the 21 pin plug, the body needs to be removed from the chassis.
First, remove the two coupler assemblies, then gently splay the sides of the body out from the chassis, then pull the body assembly upward off the chassis.
Disconnect the lighting plug from the socket on the PCB before totally separating the body from the chassis. Set the body assembly aside.
The 21 pin DC board and speaker enclosure are removed. Two screws hold the enclosure to the chassis.
Next, fit the decoder (upside down) and DCCSound premium speaker. The speaker can be held into position using Kapton tape or double sided foam tape.
Finally, refit the four screws under the chassis along with the couplers.