how to disconnect stock alarm?

[tomcat80]

I have the stock car-alarm together with a Sidewinder alarm. Have just bought the car so I dont know much about the alarms, but i hate having both of them cause sometimes the alarm goes of when i dont press the alarms in the right order.
Can anyone tell me how to disconnect the stock one? I guess the sidewinder is the best? It's a DEI, they are godd aren't they?

 

[Bd1000Eclipse]

ground your door lock relays.. but now you wont have keyless entry or automatic door locks..