Destroy All Humans! PS2 (.PKG Files)

[phantaton]

Hi, I recently found a demo of the game Destroy All Humans! that is based on one of the later betas and I am wanting to go through the game files to check to see if there's cut beta content mistakenly left in the build. I tried looking through the files and it seems that a lot of files are packed using a .PKG archive format. The usual structure of said files in a folder are the following:
DISCARD.PKG
(foldername).dir
RESIDENT.PKG
If anyone wants to take a look at this, some samples of these files are located here:
https://drive.google.com/open?id=168qbR-wAFYgUbqyhCFGs92Qp59v2jieh
I would also like something to modify/repackage .pkg archives so I could patch some of the game's files if scrapped content is found.

[aluigi]

Added soundstr and soundres at index 3 and 4, script 0.1.2:
http://aluigi.org/bms/destroy_humans_ps2.bms