[Sirrotica]

I use a length of wood (trim, yard stick etc.) and hose clamp a flat bladed screwdriver to it, stick it in the latch slot going through the rear seat bulkhead from the inside of the car and turn it so it releases. Once you get the trunk open it's easy to remove the lock cylinder just held in by a sheet metal retainer plate held in by a phillips sheetmetal screw.
I hope this helps.