This seems to be the same situation as anpther thread here recently.
The rear bow is latched, and the trunk won't open so you can get the 5mm wrench on the bolt to manually unlatch the rear bow.
I frankly have no answer for this, I thought maybe you could manually unlatch the tonneau cover and raise it enough to sneak an arm into the bow latch, but NO, I tried this on mine and you can't raise the tonneau even one inch.
I am at a loss what to do, other than say this :
REMOVE THE PLASTIC LOCKING THING FROM THE ELECTRIC SOLENOID BEFORE YOU GET IN THIS SITUATION !!!
( See pizzaman's thread on this )