Tom,
You will not hurt the side of the horn button with a screwdriver. More are concerned with putting small dents into the edge of the steering wheel next to the button. The tabs are approximately in the
2 o'clock, 6 o'clock & 10 o'clock positions as you look at the button. I would apply pressure in those three areas. Once you remove the button you will see the three mating tabs on the internal button.
Craig
My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear
My truck ....... Respect The Rust
If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.