Bathaxx is an exploit found in the game LEGO Batman. The exploit was made by Team Twiizers & lewurm.
(Official Video guide here: http://www.youtube.com/watch?v=g4paz0Z9QYY)
0. Play the LEGO Batman game at least once and back up the save file to a safe location.
1. If there is a "Private" folder on your SD card, rename it to Privateold (or something else).
2. Download the Boot.dol/elf to execute (for example the Hackmii installer, the boot.elf is in the hackmii_installer folder so you can copy it from there). Place it in the root of the SD card (this means: not in any folder).
3. Download the Bathaxx pack and place the Private folder from the Zip in the SD card root (where the original private folder was).
4. On you Wii, go to the Saves management (Wii Button -> Data Management -> Save Data)
5. Boot the LEGO Batman game.
Additional Hackmii installer steps:
6. You will see a Scam warning screen.
Wait for the message at the bottom to appear, then press 1.
7. You will see a screen like this one:
Depending on your Wii, it will show different things behind BootMii:.
Now we get to the main menu, where we can install everything.
First install the Homebrew Channel (choose Yes, continue).
The Homebrew Channel will now be installed on your Wii.
Optional (Recommended) Steps: Installing BootMii
BootMii is a helps greatly with Brick protection and it is recommended to install it.
It is not required however.
These steps don't work on WiiU
8. In the HackMii main menu, choose BootMii... and press A. You will get another menu.
9. Before BootMii will work, we need to prepare our SD card, so do that first with the third option.
10. Install BootMii as IOS. This will always work.
11. If you're one of the lucky winners, choose install Bootmii as Boot2, then Yes, continue and let it install.
Once you're done, return to the Main menu and choose Exit. It will reboot the Wii.
If you installed BootMii as Boot2, the BootMii menu will appear every time.
12. Don't forget to restore your old private folder if you had one!
So, was that it?
It mostly depends on what you want to do. Many Wii applications will already work for you now.
However, if you want more, like backup loading, custom themes, etc; you will need to continue below.