Instructions
Insert the SD card into the "SD Card Slot." on the front of the Wii. Turn the Wii on. Wait for the Wii Channel Menu to load.
Select the "Wii Settings." icon at the bottom left of the Wii Channel Menu.
Select "Data Management.". Select "Save Data.". Select the "Wii" tab.
Select the file that you want to transfer to your SD card.
Select "Copy". Select "Yes.". When asked to confirm, select "Copy to SD card.".