If your goal is to "update" the game to restore online functionality after the official Nintendo Wi-Fi Connection shutdown, you must patch it for the private server.
Go back to the tab, check the box next to Mario Kart Wii, click Transfer , and select Drive 1 . mario kart wii ntsc wbfs upd
Once your WBFS file is properly placed, you can unlock modern enhancements, custom tracks, and revived online multiplayer features. Restoring Online Play via Wiimmfi If your goal is to "update" the game