Ok, the circuit in this mdoel is easyer (because is single layer, so everything is in one side of the board), also there is a high quality photo in psdevwiki where it can be seen the whole circuit
The probem in this board is it have only 2 leds at the corner (1 red and 1 blue), but are "driven" together by the same transistor
I think i mentioned it before, but i will try to explain it again, all the leds of the board (except the eject led) are "controlled" by transistors. The led have his + (positive) pole soldered permanently to a big 5v rail, and his - (negative) soldered to the transistor
In theory... syscon should send a control signal to the transistor, and the transistor is the responsible of "closing" the subcirtuit of the led (by connecting the - pole of the led to ground)
In plain words... we are enabling the leds by connecting his - (negative) pole to ground... and we use to do it by soldering a wire to the transistor pin (or his nearby alternative solder points, or in the connector)
This is the basis, what can be seen in this photo, im joining together the - poles of the 2 leds in the corner... with the - (negative) poles of the white leds (there are 4 white leds btw, all them connected together)
The result is the 2 leds of the corner (1 red and 1 blue) are driven together with the 4 white leds
The problem to chieve what you want to do is you need to remove one of the leds and solder it in the other traces at his right
Think in them as a total of 4 leds... but connected in 2 groups of 2 leds each
-Group A have 1 red and 1 blue
-Group B have 0 leds