On the side of the carb, to the left of the air/fuel screw theres a peg that sticks out w/ a hole in it. But the hole doesn't go anywhere.
You gotta grind down that flat. Right now, its on an angle.. You have to make it flat so the nut on the new idle screw can lock properly.
Use the drill bit provided, drill through that hole all the way until you poke through inside the carb. Go slow so you don't damage anything.
Use the provided tap & some kinda oil- WD-40 etc & run the tap all the way in until the threads on the tap are all gone. Back it out & clean everything up real good. Make sure you remove any burrs on the inside of the hole.
You'll notice that when the new idle screw is threaded all the way in, the tip of it pokes into the carb. This spot lines right up with a ramp on the throttle slide. The farther the screw is turned in, the higher the idle. The kit should come w/ a new carb cap & throttle cable.
Its nice being able to pop your carb out in about 2 minutes to clean it out, change jets etc...