I3 (US) Firmware v74.40521: can't backup firmware to upload/mod it

[hobesman]

Alright, so in the meantime while I learn the ropes of what's going on here with modding the files, I wouldn't object if someone would be so awesomely helpful as to beat me to it. I think I'm already in over my head as it is trying to figure out which files to look at once I unsquash it. Here's the link for the firmware if anyone can help.

InnoTab 3, US, v74.40521

http://www6.zippyshare.com/v/uaCswCU9/file.html

One step at a time! But if we can get this working, it'd be much appreciated. It's so close to being a useful gadget!