Instructions
Push your SD card until it clicks into place in the SD card port on the front of your Wii console. You'll find the port behind a small plastic door on the front of the console. If you're using miniSD or microSD cards, firmly connect your card to its full-size adapter before inserting it in the machine.
Turn on the Wii console. Start the Wii options manager by clicking the "Wii" icon in the bottom-left corner of the main menu.
Click the data management system, then choose the Wii console. You are now in the Wii memory management mode. Click the SD card icon to manage the information on the SD card.
Choose either "Game Files" or "Channels" depending on what you're copying. All Virtual Console and WiiWare titles will be found under "Channels."
Look through until you find the information you intend to copy to the SD card. Click the left and right arrows to scroll through the available channels.
Click the icon for the files you wish to copy. You are then given the option to "Copy to Wii" or "Delete."
Click "Copy to Wii" and leave the machine to copy the files. This process can take a few minutes depending on really large chunks of data.