The blinking light tells you the anti-theft systems is armed. Before taking things apart you might try disconnecting the battery for 20 seconds and then reconnect. Hopefully the theft system will reset. That's a lot easier than opening the hatch through the license plate light hole. It may not work, but give it a try. You do need to replace the CLP/SSM! The siren located under the windshield plastic cowl also should be disconnected or replaced with new.