Hacking a game is rarely as easy as randomly extracting everything and then finding the dialog. There's no reason different games have to store their text the same way – even if the text in this case isn't compressed one way or another, it will almost certainly have a whole bunch of "control codes" that you'll have to manually reverse-engineer.
Do you have some reason to believe changing the text in this game should be easy? Have you already seen other people changing it?