I cant post pictures because I took the light off.
I did not like the job I did on them so I pulled them out. I wanted a setup up that did not produce too much heat and have not got around to replacing.
This is what I used.
Go over this process until you really understand it and then try. First we will go through the basic LED wiring flow.
Starting with the
Common + side from the power supply it is connects to one side of a resistor (which reduces the voltage and current flow for the LED)
The output of the resistor is connected to the Anode + side of the LED.
The Cathode - side of the LED is connected to the return side of the power supply.
Now lets look at the decoder's wiring and match them up.
The common side is the blue wire from the decoder.
The return wire is the Yellow or White wire to the decoder.
Because this was a DC power board the LED's cathode opposed each other. Remember the polarity changed on the track which switches the current flow and only one LED will work based on the position of the Anode.
In DCC the voltage polarity is not being switched. Power is being supplied by two different power sources (White and Yellow leads). Therefore we need two separate return leads that are isolated from each other.

Looking at the diagram you can see the removal or scratching of the traces (Red X )isolates the track power (Red and Black) from the LED's.
Remember the flow?
Blue wire, resistor, Anode, cathode, return.
You can see that the Red LED is fine as it is. The clear LED needs to be modified.
The clear LED need to be flipped so that the Anode is attached to the resistor/blue side of the board and the white wire is tapped onto the cathode side of the LED on the bottom of the board.
This is where you can run into trouble. You need to get the white wire to the cathode on the bottom of the board. This is added work. I will show you a better way to
scratch the traces.
This is really harder but yields a better finish.On the modified drawing I split the LED runs horizontally so we can use the existing surface material. Desolder the LED first so you can carve the runs.
Use a sharp exacto and just carve a thin but clean path to isolate the runs. This way you can keep everything on top. Don't forget to flip the clear LED when you solder it back.
The key to success if in your soldering technique. You need to have clean tip and solder fast. The traces are thin and can take only one or two attempts. Anything more then the traces will pull off the boards and you will have a mess.
Inobu