For WiiU modding, this is the way to go currently (late January 2017):
0) ignore anybody mentioning rednand, mocha, loadiine, tickets, simple "brazilian" USB loading (although the latter is technically part of what you're gonna do);
1) update your Wii U to 5.5.1 asap (before 5.5.2 is out, not saying that's a given, but it is a possibility with the new Zelda)
2) buy a suitable (for haxchi) DS game from eShop asap (again, before 5.5.2 is out); don't be a cheapstake, it could mean wasting the chance of a lifetime to perma-hack the WiiU; choose the DS game you like the least among the suitable ones, as you won't be able to play it (probably "Brain Age" is a good bet)
3) install haxchi to test if everything works before installing automatic-haxchi (as stated by every automatic-haxchi guide)
4) install automatic-haxchi (called "CBHC")
5) install "homebrew channel" on Wii U
6) install "WUP Installer GX2 Version 1.1" on Wii U
7) install "Wii U USB helper" on pc, when asked for a source of keys insert the link to the first result when googling "wii u keys"
8) find games (like CoD) that aren't in "Wii U USB helper" elsewhere, they must be "USB ready"
9) use an SD card as boat to carry stuff from PC to WiiU, and on WiiU use "Wup Installer GX2 Version 1.1" to install stuff to USB HDD; install up to 300 games
10) just play with your wii U and never touch the "hack" part ever again (except for updating CBHC), as anything (not actually) could conflict with CBHC and lead to a brick; for the love of god don't try to delete or reinstall the DS game used for the hack or you will brick; for the love of everything that's pure and beautiful in this world, don't format your WiiU while CBHC is set up or you will royally brick
11) block updates with DNS (or disable networking altogether if you don't plan to play online)
12) don't bother with hacking vWii, just grab a real Wii on ebay and don't put your fragile WiiU in jeopardy, as even a vWii related crash followed by force restart could brick your WiiU
13) come back to gbatemp in 5 years when the dust will settle for more advanced stuff (WiiU native backup USB loaders with ISO fat32 support, WiiU native emulators, etc.) if you want to revamp your mod
this setup plays anything (sigpatch) from any region (region patch), so it's better than plain simple usb loading formerly known as "brazilian method"; it loads automatically when you start your WiiU and can be used completely offline (no need to visit a website), so it feels like a perma-hack
paste this guide to any noob confused by the crapton of outdated information, word salads and stuff meant for advanced tinkerers
Wii U modding is dead simple (or limited one could say) at the moment. This video is straightforward as it gets, just use up to date files (WARNING: could be outdated if you're reading this past January 2017):
