Mods do not include game data. You must provide a clean, unmodified or WBFS file of the original game.
For Newer Super Mario Bros. Wii , set Shake to a key (e.g., Q) – needed for some moves.
Now that you know to install them, here are the mods worth playing.
Once you've added the game to Dolphin, select it from the library and click "Launch." The game should now load, and you'll be able to play it like you would on a Wii console.
Some smaller mods are distributed as standalone .wbfs files. In this scenario, no patching is required. The user simply proceeds to load the file in Dolphin.