immobiliser bypass

I have a Nissan Serena 2.3 Diesel 1997.The little immobiliser light on the steering collumn no works and I can not start the engine also my indicators and horn do not work when ignition is on.obviously the immobiliser cuts the ignition.Does anyone know how to bypass it.I don't want to go to a Nissan dealer and pay hundreds of pounds,I would rather just take the immobiliser off altogether.