|Tape the horn button down with a piece of masking tape or have someone hold the button down for you. Now insert the light switch spider over the legs of the tool, slide the spring onto the spider and push them both onto the horn rod making sure you have the ears lined up correctly. Push far enough so you can install the retainer, then remove the tool and you have just installed the spider and retainer easily. The spring A3642 and Spider A3643 are sold separately.
"Mikes A Fordable Parts-Model A Ford Light Switch Spider Tool Instructions"