I have managed to break the rear window in my R reg Diesal Freelander (a shovel fell against it from the inside!).

The accidental break has caused the dead-lock to become activated so no matter what I do I cannot open the rear tail-gate (I believe the alarm system probably believes the accidental break is a theif trying to steal the vehicle).

Problem is that I need to open the rear tail-gate to fit a new rear window.

Any advice would be very gratefully received.