I know its an old post but...
I just did this last weekend for the same reason you stated, I am running 265/75r16s (31.5x10.5) on 3.55 gears and when she kicks into second on a long down hill its frustrating to have to ride the brakes all the way down. VERY simple mod and only took me about 15 minutes. I got my hands on a cool switch cover to prevent the passenger from flipping it when I am driving down the road. It simply prevents the soleniod for second gear from getting power. My AW4 is in a 93 but I have heard bad things about 98 and newer giving trouble codes and such. It does not do anything when the switch is flipped out of the 1-2 but when it is in 1-2 it works GREAT!