Simply, you cant. the immobiliser not only stops the engine from being started, it also alters the ignition timing to stop the car being Hot-wired. If the unit you have is a Thatcham approved system then all of the connecting wires will be black with a number of them being decoys ie disconnect the wrong one and you will deactivate the whole system. Not only that, your insurance will be invalid if you tamper with teh system.
Lofty, November 2005