The master cylinder push rod rotates, so you can rotate the end 45 degrees out, put the brake switch over the top of the push rod, aligning the holes, and then rotate both onto the shaft together. If I remember right, there's a plastic washer that goes on the shaft first, then the switch/pin and then another plastic washer with the slide pin to secure everything. Honestly, it shouldn't take more than 15 minutes. If you're a big guy, Jim's suggestion of removing the seat may be best.