No Homebrew Channel, no SD card, no USB device, no technical knowledge required, just a Wii and an Internet connection like the good old days. Simply follow the video, and check the bottom of the description if you run into trouble!
For those who don't know, Wiimmfi is a custom server that allows users to play Wii (and DS) games online after the Nintendo WFC shutdown. This includes games like Mario Kart Wii, Super Smash Bros. Brawl, Mario Strikers Charged, The Conduit series and many others as well. Recently, new developments have made this custom server accessible to almost everyone, regardless of how familiar you are with computers, homebrew and the like. This video is a demonstration of the newest technique that can be used to access Wiimmfi!
Thanks to a new bug recently discovered in the Wii's Internet Channel by Fullmetal5, it is now possible to run homebrew or other unsigned code without needing any external device at all, and because this presents such a cool opportunity to get more people to use Wiimmfi due to how simple and accessible this method is, I simply had to make a video about it! Do send him credit for such an awesome find!
Regrettably, this method does not work on a Wii U, due to the fact that you cannot download the Internet Channel onto a vWii.
Please note that you will have to go into the Internet Channel and select Wiimmfi from the favourites every time you want to play online. The patch does not persist after you close the game. Be patient if it doesn't work the first time! If you want a more reliable, albeit more complicated way of getting Wiimmfi, see this video: https://www.youtube.com/watch?v=RqFtklrXY9M
Also, if you're wanting to do this with a USB loader or similar... you're late to the party! Because there's been a tutorial out on how to do that for over 3 years now! Check the second half of this video for details: https://www.youtube.com/watch?v=RqFtklrXY9M
I hope that everyone finds this video useful, and I hope to see some new faces online using this :)
Troubleshooting if you have problems:
Japanese users may not be able to use this technique, right now the NTSC-J Internet Channel may not be supported. But it probably will be soon!
Korean Wii users cannot use this technique, as the Internet Channel is not available to Korea. Nintendo never released it. Korean players will have to follow the other video linked above, instead.
European/Australian/PAL Wii users should make sure their Wii is set to 60Hz (either 480i or 480p mode), as this method currently does not work on 50Hz. (Wii Options - Wii Settings - Screen - TV Type - 2nd or 3rd option, 3rd is better quality but not everyone can pick it).
I've heard rumours this also doesn't work if you launch the Internet Channel from the SD card menu, so you should also make sure that you launch the Internet Channel from the Wii Menu instead.
If the Wii freezes or locks up when visiting the website, simply hold the power button for 4 seconds, then try again. It may take a few attempts to get it going. Some things you can try to improve reliability are erasing your cookies (Settings menu in the Internet Channel), erasing the Internet Channel save data (from data management), updating your console to the latest version, setting your console language to English, and trying to go as fast as possible to the favourites as soon as the Internet Channel loads. If none of that works, you could always redownload the Internet Channel.
If the Internet browser does not look like the one in the video, it may not work. Download it fresh from the Wii Shop if that happens.
If you get Error Code 23899 or 23887 or anything beginning with 238 when connecting to Wiimmfi, this is normal. All new users to Wiimmfi must wait 1 week before they can play on Mario Kart Wii. Receiving one of these errors simply means you need to wait a bit longer. Other games will not have this issue. (Please note: Anyone who's reading this who hasn't received one of these errors in MKW and is new to Wiimmfi, you must attempt to connect to Wiimmfi once in a game, otherwise the week countdown won't start. Just visiting the website is NOT enough!)
Error Code 20110 would indicate the patch has failed. Try reloading the browser.
If you get Error Code 60000 when connecting to Wiimmfi, if it is Mario Kart Wii, use a brand new license, if it is any other game, erase your friend code however you can (start a new save or similar) and then try again.
Any other Wiimmfi error code can be looked up at http://wiimmfi.de/error.
Thanks for watching!