Can any body tell me how to replace a horn button on a sammy?

If you take the cover off of the steering wheel you will see the write/metal that is used.  To replace the 'horn button' you will need to remove the steering wheel completely.  The horn goes between the steering column and the steering wheel.

Did you ever test your horn button to see if the problem is just a loose wire or a bad horn?

Yes the horn works. The button itself was defective. I found a replacement thought it would snap into place..It wont. 

Which half of the horn is defective?  It is a two piece unit, you should be able to reach up in between the steering wheel and the steering column and press the two contacts together and make the horn work.

To replace the horn switch you will need to pull off the steering wheel.