Removing Overdrive switch

I remember doing it when I first started the restoration of my 86 model, but since then I've forgotten how its done. Can someone refresh my memory on how to take out the Overdrive switch. I've already taken out the cover from on top of the shifter knob. I've also taken out the "T" rod in the center of the shifter knob. What I've forgotten how to do is where is that nut that I'm supposed to loosen to enable me to take out the shift knob itself! Any help would be appreciated.