It was pretty easy. I removed the butterfly off the choke and the shaft came right out. Be careful though there is a small ballbearing and spring that puts tension on the choke shaft. Dont lose it!. Then I just used a std JR servo arm with the center reamed out to slide on the shaft and used a small screw (2mm or 2-56) bolted on the choke arm. Then I reinserted the choke shaft into the carb, (dont forget the ball bearing and spring) and then screwed the butterfly plate back on. Works Very Well!!