Extracting PKG files from the Xbox 360 version of Deadly Premonition

[JMCganer]

Hi, I'm new to this site and I'd like some help figuring out how to extract the PKG files from the Xbox 360 version of the game Deadly Premonition. 

I searched the entire internet and forums and found nothing related to this type of file on Xbox. The Magic file format is "XZP"

So if anyone can lend a hand, here's a sample file below.

messagePKGfile.zip