Put your SD card in your computer’s SD card reader. Create a folder called “apps” (without the quotes) in the root folder of the card.
Now you need software, so go to wiibrew.org.
Choose an application listed at wibrew.org and click on it. This will give you a description of the software, with links on the right hand side to download it or visit the developer’s website.
Click on the download link. This will either start the download immediately or take you to a website from which you can download the software. Software will be in the zip or rar format, so you will need appropriate decompression software. If you have Windows you can use something like IZArc or Quick Zip.
Decompress the file into your SD card’s “apps” folder. Make sure it is in its own subfolder. For example, if you install SCUMMVM, you would have a SCUMMVM folder inside of the apps folder.
Put as many applications and games as you like (and that will fit) on the card. Now take the card out of your PC and put it back in your Wii. From the main Wii menu, click on the Homebrew Channel and start it. You will now see anything you installed listed on screen. Click on the item of your choice and enjoy.
Note: The easiest way to find and install homebrew software on the Wii is with the Homebrew Browser. If you install HB using the method above, then you can just put the SD card back in the Wii slot, start the homebrew channel, run HB and choose and download the software you want. HB does not list all the software available for the Wii, but it lists most of it.
