After you completed the following
MattKimura's Wii U hacking guide ←(you only need steps I-III)

1. Download the game files which contains 258 files, i renamed the '00050000101C9500' folder to 'Z1' (final version with the uncorrupted files should be 259 files, 10,551,280,012 bytes)
2. Download the .tik file and rename it to title.tik (be sure you have extensions enabled or you can mess up and rename it to title.tik.tik if your extensions are hidden)
3. Place the title.tik files in the game folder (you should now have 259 files with the tik added on)
4. Download the update (the one from MEGA) and put it in a folder named Z2
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 Z1=the actual game and Z2=update)
[Also installing on NAND is much quicker than USB]

6. Insert the SD card into the Wii U and turn it on
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 install GX2 → install the Z1 folder first.
9. For safe measure reboot and repeat steps 6,7 &8, but this time install Z2, the game update.
10. (Optional) Go to your internet settings of the WiiU → your connection and change the connection SSID name by adding a 0, that way your wiiu isn't connected once you start your gameplay just as a precaution so your WiiU doesn't get banned!
11. Once both files are installed press home, exit MiiMaker, start the game and have fun


Error: If you get an error saying something about Sig patcher, you can download and install an app from the HomebBrew App Store under 'Tools' named 'SigPatcher2HBL' and/or 'SigPatcher2sysmenu', load them and retry install!

Enjoy.

Remember if you don't want to play this game using your WiiU pad, you can install HID TO VPAD from the HomebBrew App Store under 'Tools' and play BotW using your PS4 controller! (tutorial for that is also in MattKimura's Wii U hacking guide)

Also check out my mini guide on how to reduce frame-rate drop/lag in the game


(Anon from 4chan helped make this!, this is his discord https://discord.gg/ADxvY3h)
And a Special shout out to Frenchbro for providing us with the tik!