Wendell, what did you do to get n key on your model m?

Finally able to watch the tek from last week and you mentioned an NKRO model M. What did you do to get that? I know copper foil and soldered on diodes, but like how? I have a unicomp endurapro, yay nipple mouse, which as far as I know uses the exact same membrane and stuff the old model m did, and I really want to do this over spring break now.