How can I bypass my kangoo authentique immobilizer?

My Renalult Kangoo Authentique does not start and there is a red light on the dashboard that flash quickly. I tried everything to (lock and unlock the doors etc) but still the problem persists. Sometimes she starts without problem sometimes i can't get rid of the flashing light. I should bypass the immobilizer but who knows how to do it? Thanks for your help!Garssendi