disabling horn chirp 2003 toyota matrix

I have a 2003 Toyota Matrix with a factory alarm and I would like to disable the horn chirp when arming/disarming the alarm.   I found the following in another thread:

|       ITEM      |     WIRE COLOR     |POL|       WIRE LOCATION        |

|              12V|white & black       |+ |ignition harness            | |          STARTER|red                 |+ |ignition harness            | |        IGNITION|BLACK/ white        |+ |ignition harness            | | SECOND IGNITION|BLACK / YELLOW        |+ |ignition harness            | |        ACCESSORY|blue/red            |+ |ignition harness            | |       POWER LOCK|green *1            |- |passenger kick panel        | |     POWER UNLOCK|blue/black *1       |- |passenger kick panel        | |       LOCK MOTOR|blue               |   |driver kick, door harness   | |     UNLOCK MOTOR|red                 |   |driver kick, door harness   | |    DISARM DEFEAT|red                 |   |driver kick, harness to rear| | PARKING LIGHTS +|green               |   |driver kick panel           | | PARKING LIGHTS -|GREEN / WHITE        |   |headlight switch            | |       HEADLIGHTS|red                 |- |headlight switch            | |     DOOR TRIGGER|RED / yellow          |- |driver kick panel           | | DOME SUPERVISION|comes on with unlock|   |                            | | TRUNK/HATCH PIN|common with doors   |   |                            | |TRNK/HTCH RELEASE|blue/white          |- |release switch on dash      | | FCTRY ALARM ARM|arms with lock      |   |                            | |FCTRY ALRM DISARM|disarms with unlock |   |                            | | DISARM NO UNLOCK|blu/blk (key sense) |- |ignition harness            | |       TACHOMETER|black *2            |   |pin 5, conn. 4 @ PCM *3     | |      SPEED SENSE|PURPLE / white        |   |pin 17, conn. 3 @ PCM *3    | |       BRAKE WIRE|GREEN / WHITE        |+ |brake pedal switch          | |     HORN TRIGGER|GREEN/ YELLOW        |- |steering column             | | SUN RF OPN/CLOSE|green - red        |A |sunroof switch assembly     | |   SUN ROOF LIMIT|grn/wht or RED / blu |- |sunroof switch assembly     |

 Would I just need to disconnect the GREEN/ YELLOW wire in the steering column harness ?

If you disconnect that wire, the horn button on the steering wheel will no longer work either. You would have to look in the owner's manual to see if the factory system offers a silent arm/disarm option.Installer, IT support, and FFL. I need less hobbies.