Well I am not sure why he did it that way but perhaps his jack ends are a little different. It is very simple as far as wiring, so it here it goes:
O/S, G/S, B/S and B/S all get wired together and get connected to any of the positive terminals on the MR16.
Orange solid goes to Channel 1 GND
Blue solid goes to Channel 2 GND
Brown solid goes to Channel 3 GND
Green solid is not connected to anything.