Things You'll Need
Instructions
Installing the Homebrew Channel (Wii System 4.2 or lower)
Determine your Wii's system version by turning on the system and selecting "Wii Options" in the lower-left corner of the screen. Click on "Wii Settings" on the right-hand side of the screen; the version number is displayed in the top-right corner of this screen. Nintendo has engineered systems 4.3 and higher to detect and block hack attempts. If you have this system, you will not be able to hack your system without downgrading your system menu. Guides for doing this can be found online, but they change often because Nintendo releases new updates.
Download the Bannerbomb exploit and the HackMii installer from the Internet (see Resources).
Insert the SD card into your computer's SD card reader, and wait for it to recognize the card. If this is the same SD card you have used for your Wii, open it and rename the "Private" folder to "Privateold."
Unzip the contents of the Bannerbomb exploit. This should create a "Private" folder with the contents of the zip file. Put this folder on the SD card.
Copy the "installer.elf" file from the HackMii installer onto the SD card, and rename the file "boot.elf."
Eject the SD card from the computer, and insert it into your Wii.
Turn on the Wii system, and click on the circular "Wii" icon in the lower-left of the screen. Do not click on the "SD" icon if it appears; the Wii will not be able to read the files. The "Wii" icon will take you to a sub-menu.
Click on "Data Management," select "Channels" and choose the "SD Card" tab at the top of the screen.
Click "Yes" when the Wii asks you "Load boot.dol/elf?"
Hit "1" to continue after the second warning appears. At this point, the HackMii installer will become your Wii's temporary operating system.
Select the option entitled "Install the Homebrew Channel," and confirm that you want to install. After a few seconds, the Channel will let you know it has been successfully installed and will boot up the Homebrew Channel. If you have any files in your SD card's "Apps" folder, they will show up here. Otherwise, the screen will be filled with a default bubbles screensaver.
Reset the Wii. It will take you back to the Main Wii Menu, where you will see the Homebrew Channel among the other channels.
Installing an older IOS (Wii System 3.3 or higher)
Download DOP-Mii, and extract the zip file onto your SD card, keeping the folder structure intact.
Insert the SD card in your Wii, and launch the Homebrew Channel.
Select DOP-Mii from the Homebrew Channel, and choose "Install I0S36 (v3351) w/FakeSign" from the menu.
Confirm your way through the next several choices to apply the ES_Identity patch, the NAND Permissions patch and to download the patches. When DOP-Mii asks you if you want to restore the IOS15 to another version, confirm that you do. When this is done installing, turn off the Wii and put the SD card into your computer.
Download the cIOS installer, unzip the file and put in the "Apps" folder on your Wii SD card, keeping the folder structure intact.
Put the SD card back into the Wii, and launch the Homebrew Channel.
Launch the cIOS installer. On the initial screen, use the right and left keys on the Wii-Motes directional pad to switch the ISO number to ISO36. Press "A" to confirm.
Use the keypad to select Network Installation. Press "A" to confirm. Soon, the system will confirm a successful installation.
Press any button to reboot the Wii. At this point, your Wii has been configured with a system version that can use an external hard drive.
Using an external hard drive
Download the WBFS Manager that best fits your operating system (see the list in Resources to help you pick out the right one).
Start up WBFS on your computer.
Plug your external hard drive into your computer. Using WBFS's pull-down menus, find your hard drive and click the "Format" button. This will erase your hard drive, so make sure all of files that you want to keep are copied first. Also, be sure to select the right drive, or you'll end up erasing your computer's hard drive instead.
Shut down WBFS, and eject your hard drive.
Plug the hard drive into the Wii's USB slot. This is located on the back of the Wii and is labeled "USB." If your Wii has two USB slots, use the bottom one; the top one is for accessories.
Go to the USB Loader GX site (see Resources), and download the most current .DOL and .WAD files.
Place the .DOL file on your SD card in the folder "apps/usbloader_gx" and rename it "boot.dol."
Put the .WAD file in the "wads" folder.
Insert the SD card into your Wii, turn on the system and navigate back to the Homebrew Channel.
Launch the USB Loader GX.
Insert a game into the Wii system, and click on the "Install" button.
Wait while the system downloads the game data.
Install as many games as you like onto the hard drive.
Press the "1" button on the Wiimote to download game covers.