Format the SD card:
1. Find an SD Card (supposedly it needs to be at least 16gb) - Note, mine is a 128gb which seems to work fine
2. Format the card to Fat32. The tutorials I read said to use 64kb or 32kb cluster. I used 32 and it worked fine
3. Do not name your card "wii U" or "wiiu" - this causes an error
(Stolen from this tutorial: https://gbatemp.net/threads/mattkimuras-wii-u-hacking-guide.462121/)

Put the files on the card:
! Before you proceed, download this zip and extract everything to your SD card. Replace if it asks.
This will save you time with file work and keeps you ready for the steps below​
https://mega.nz/#!KlZBmbLS!oureEv3ggEiRpRoeyDno9EBLpeOUgvIMbtkVGtJ4oyw

Block Automatic System Updates:
1) Go to System Settings
2) Go to "internet settings", "connect to the internet", then touch "connections" on the top right, and choose your connection
3) Go to change settings, then scroll to the right
4) Choose DNS and set it to not auto obtain
5) Set the primary as 35.164.240.189 and the secondary as 168.235.092.108 (For EUR users, use 81.4.127.20 for secondary)
(This comes from this DNS server HERE )
6) Save the connection setting, no need to test it after

Use CFW:
1) Put the SD into the WiiU, go to system settings. Under power settings, disable "Standby function" and "Quickstart menu". This can cause problems with CFW down the line.
2) Launch the Browser on the WiiU. Go to Bookmarks and edit any existing bookmark. Change the name to Homebrew Launcher, and the URL to loadiine.ovh/550/HBLK . Edit another bookmark with the name Mocha CFW, and the URL wiiubru.com/mocha
3) Load the Mocha CFW labeled bookmark and you'll be brought to a page. Simply click the brown button called "Add the chocolate" and Mocha will launch. The gamepad screen will display Mocha CFW then return to home menu, but with signature patches enabled

Note: If you see a grey screen, you might need to re-format your SD card, or rename it (remember, don't call it "wiiu" or "wii u"). My other theories include (but are not verified): Your SD Card might suck, or you didn't put the files on the card correctly.

Install a game (I'm installing Zelda BOTW):
1. Download the game files (258 files)
2. Download the .tik file and rename it to title.tik (be sure you have extensions enabled or you can fug up and rename it to title.tik.tik if extensions are hidden)
3. Place the title.tik files in the game folder (you should now have 259 files according to math)
4. Download the update (I got the one from MEGA)
5. On your SD card you need to have a folder called 'install' where you will place the game folder and the update folder (name those 2 folders however you want)
6. Insert the SD card into the Wii U
7. Run a CFW (Mocha doesn't require anything special to set up so use it if you don't have one)
8. Run homebrew channel -> wup installer mod y -> install both folders (game and update folder in this order)
9. Start the game and have fun
6. Make sure you have wup installer mod y and use it to install those folders