"Do they go in from the top "--If I remember correctly, yes. You have the cancelling cam, then you put the spring in the only hole in the cam from the top, and then you push the horn contact/button into the spring in the cancelling cam. The contact should fit inside the spring, and the flanged part should be pointing away from the hold in the cam (so that the flange rests on the cam hole when the spring is all the way compressed) Don't let go quickly, or it will go flying across your garage. I know it looks like the only way to get it to stay is to remove the metal on the bottom of the cancelling cam, but that's not going to let the contact actually make contact with the metal that makes the circuit. There's a photo here, but it doesn't have the sequential order of installing the parts in the cam that you're looking for: http://www.jeep-cj.com/forums/f49/or...g-wheel-13946/
Hope this helps, it's been a couple of years since I had to do this to pass state safety inspection.