I'm trying to do the same thing, but i'm having trouble for that. By the way, since they are official wads (official Wii content), you don't need to convert the wads to vwii. The only wads you need to convert to vwii are the homebrew apps (like emulators, and that type of stuff).

welp now i know how to get the dlc btw dlc cant work with games with sd card works with usb inject the games with uwuvci download the bogus wad with wad2bin dont forget to extract your wii keys thats it. you can patched the game with wii mart before uwuvci but thats optional