Reach up under the dash, right behind the start button. Find the Gray plug which is facing upward. Thats the plug which is plugged into the RKE module. Cut the orange wire. You will never hear the horn again when you press the remote 2 times, nor will it go off when you hit the panic buton. The horn will still work when you hit the horn button on the steering wheel.

OR:

Just hit the lock button once on the remote. Same effect.

 

Great info, i am not cutting anything but you know your wires

 

OP, if your keyfob has a panic button, you can hold down the lock and unlock buttons for 5 secs and it will toggle beep/nobeep modes. if you dont have a panic button, then just push lock once.

 

Just tap into that wire and add a siren, real easy.
pick any siren youd like.

 

Only as long as you add a relay. That wire is the horn relay actuator ground.