i've tried it by extracting the opening.bnr file from the ISO and saving it as 0000000.app then changing the game ID in the 0000001.app file to the ID of new super mario bros wii, packed it all up into a .wad, gave it a new save ID but it just green screened when i tried to start the channel from the SD card menu.
i cant remember what method that is, but its based on waninkoko's usb loader 1.1 i believe.
i dont think alot of people use this method anymore but i do lol, learnt it from here but cant remember where the topic is, it was ages ago obviously since it was when USB loader 1.1 was released lol
it's really hard to explain lol