The board will need several modifications as you can check in the following photos:
- Remove the clips of the cooper pieces that pass current to the motor, isolate them with Kapton tape and place them again in place
- Remove the capacitor to avoid problems with DCC operation (blue arrow)
- Cut the cooper tracks as indicated in the following photo with the red arrows
- Solder the decoder wires in place and do not forget to bridge the led with the right cooper track (check the red short wire in the left of the board as shown in the photo)
Decoder must fit under the green plastic piece and you cannot skip this plastic piece because it isolates the motor from the track current. Remember, DO NOT TEST IT IF THE GREEN PLASTIC PIECE IS NOT IN PLACE.