Installation of an ESU LokSound V4.0 decoder into a TrainOrama GM/42/S involves a few simple steps. Remove the body by splaying out the body and gently lifting it off the chassis, taking care to support the chassis appropriately.
Remove the existing speakers.
Remove the dummy plug from the DC board.
Plug in the decoder and position the speaker(s) over the chassis as shown.
Run a bead of Miscoscale KrystalKlear around the perimeter of the speaker enclosure to seal up the gap to the chassis (shown in white below).