The warning tone is there to notify you that you have your car in reverse - duh.
Take note that I'm not going to go into the nitty-gritty of naming every screw location because If you can't remove a few screws, leave it to someone with an IQ higher than your shoe size.
To get around this, do the following:
1: Remove the dash surround, knee panel, and key panel. You should end up having something looking like this:
Keep in mind that I've removed a lot more than what you need to because I am wiring up an 8.1 DVD system in the car while I'm doing this.
2: Remove the dash cluster.
3: Remove the 2 screws holding in the alarm:
4: Take note of the screw that I'm pointing to. This is the +12v positive feed for the alarm. Once you remove the screws and alarm, place a blob of silicon, gasket silicon, or butyl rubber over the PC film to insulate the screw hole. You probably don't need to do this, but it's best to be safe than sorry.
5: Put it all back together and enjoy.