You should be able to just drag the AirPort Utility app from the Utilities folder (located in the Applications) to the trash.
There's also the:
/System/Library/CoreServices/AirPort Base Station Agent.app
But I wouldn't mess around with that.
Though I'm curious as to why you would need to do this, as it only stops you from configuring your AirPort equipment.
If say you didn't want someone else to be able to configure it then you don't tell them the password.
Though at-least grabbing the AirPort Utility from Apples website to reinstall it should be fairly easy, unlike a lot of the other built in applications.