The installation is for HO-Scale GSB SD40-2W. It uses T1 decoder and was performed by Jean Lacroix
This model was custom painted in CN colors and modified by adding a Canadian wide nose cab.
In order to remove the body, you will have to remove the 2 screws that hold the plastic fuel tank underneath the locomotive.
Two other screws, hidden by the white metal fuel tank, holds the body and you will have to remove them as well. The body should now come off easily.
You will then have to disconnect all the wires, red and black, that are hooked on the two motor poles.
The red wire sits on top of the motor and the black wires run underneath part of the frame and is somewhat hidden. The best way to cut the power that runs in the black wire is to cut it as shown in the picture above.
You will solder the orange wire from the harness on top of the motor and the grey to the contact of the motor located below in between the frame. Then, solder the black wire of the harness to the black wires that come from both trucks and the red one to the red wires that power the other side.
The blue and the white wires are connected to the front headlight Led as per instructions that come with the T1. The Led was then glued in the clear lens located inside the nose of the locomotive. The yellow was not used for the backup light. Cut back the violet and the green and put liquid tape or electrical tape at their ends. Make sure you use shrink tubing over each connections between wires. The decoder can then simply installed just in front of the big weight that sits on top of the motor or on top of the front truck and held in placewith double sided tape. You are now ready to reinstall the body doing the opposite of what you have done earlier.