How to upload custom Minecraft skins to xbox 360 using a flashdrive?

My sister and I just got the game and we use split screen. Unfortunately, while I have access to Xbox live, she does not. Besides, she wants to use a skin of her own design which she made using http://www.minecraftskins.com/skin-editor/ and does not care for the ones offered through a gold membership.

I'm hoping there's some way to save it to a flashdrive and plug that directly into the xbox; there seem to be the ports for it, but I've searched the internet high and low and can't seem to find any proof that anyone has tried it.

If there's a way, can you give me some additional directions or maybe a link to some?

You can't you can buy skin packs the reason why you can't do that is because of copyright laws like you could download a Mario skin and that would be copyright from Mario so you can't really and those ports are for usbs where you save profiles and game saves but not minecraft skins that wouldn't work