uhhhhh.... you might want to explain some of the gibberish youve posted if you actually want some results.
You carnt, wxPirs will only read / extract 360 containers. I think you can build your own with Le Fluffie - link I built my own theme with that, a modded demo will not work unless your console is jtagged... in which case you wouldn't need to re build the demo in to a container anyway.