I did it a few times on my old cars but not really sure this will work.
Take a wire coat hanger cut the wire at the hook leaving the hook intact. form an 'L' shape with the hook about 2" long and slight up ward angel.
Lay the hook flat on the window inline with the lock button/knob and ease the wire down past the rubber window seal working it past the window cradle. Go down about 3/4 depth of the door turn the hook towards the inside of the cab slowly draw the wire up and hopefully the hook will pull on the lock button rod and release the lock. Good luck.
To critics this method might not work on modern vehicle but lets face it thieves don't give a s..t and us a brick.
The alternative is to price up new rear window fitted against a the price of a vehicle locksmith, bear in mind you will need a new lock.
bob
February 2014