Contrary Horn Button 308

My horn button is rather contrary. It honks if you push at 12:00, sometimes works at 3 and 9, and seldom at 6:00. I took it off to clean the contact areas but they are inside the horn assembly. I carefully sprayed some contact cleaner inside (afraid to ruin the Horsey) but no help. Has anyone taken the horn assembly apart without breaking the plastic?? Anything to watch out for to avoid ruining the thing?? Thanks.