Have a Saab 9.3 convertible and the motor which unlocks the 5th (locking) hoop has died. How do you unlock it?

Have tried to power the motor independently of the car's elctronic control, to no avail. The motor seems to be either jammed or broken. As the convertible toneau is currently up, there seems to be no way to unlock the compartment as access to the motor and locking mechanism depends on being able to get the cover down. Classic catch 22. Sabb dealers in Australia are 1500 km away and they (by phone) seem unwilling or unable to provide any magic solution as to how to unlock the motorised catches holding the cover shut. Help!