Rear hatch wouldn't open...ASAP HELP
 

So a few weeks ago the rear hatch stopped working all togeather. Took all the panels off and basically came down to the realization that something inside the lock mechanism broke and I can't manually undo the lock. I bought a replacement part online. Now I am stuck at trying to figure out how to get the lock to disengage so I can actually open the trunk to replace the broken part. I attached pictures to try and help explain the situation. Any help is greatly appreciated. Really don't want to have to take this to a dealership and drop a bunch of $$ on it.