Once you remove the light board, flip the motor plates in vertical position. When you insert again the light board these plates won't be under the board, but over it. You won't need neither any Kapton tape nor isolating any point.
In the following photo I'm showing how to prepare the light board:
- Red arrow: you have to cut the track in this 3 points
- Blue arrow: make a bridge between the cooper tracks. First remove the capacitor, and make a bridge instead.
- Yellow arrow: soldering point, tin these 4 points and the motor plates
Here you can see the decoder soldered and in place:
And that's all, enjoy!!