If your car uses the factory fitted alarm, the box is located in the boot, left behind the side panel.
Use a nr. 10 spanner, three bolts later you will have it out
and yank out the two wired plugs connected to the box (Black in color). But then neither your alarm, imobiliser and central locking wont work.
I have done this when my one remote failed. The siren uses a plug so you can disconnect it in the engine bay
Good luck....