Instructions
Insert the homebrew SD card into the SD card reader on the computer.
Open the computer's Web browser and navigate to a website that offers the homebrew applications you wish to install onto the Wii for download. Download the files to the computer. Make sure to take note of their save location.
Double-click on the SD card in the "My Computer" section of the computer to open the SD card's root directory.
Right-click and select the "New Folder" option from the menu to create a new folder in the root directory of the SD card. Name the folder "apps."
Use a program such as WinZip, WinRar or Stuffit Expander to expand the contents of the file downloaded in Step 2.
Drag the contents of the file into the "apps" folder you created in Step 4. Eject the SD card from the computer.
Insert the SD card into the SD card slot on the Wii system and turn it on.
Click on the "Homebrew Channel." Click on the application you placed on the SD card to install it. Allow several seconds for the installation process to finish.