Instructions
Insert your Wii's SD card into the SD card slot on your computer. If your computer isn't equipped with an SD card slot, use an universal serial bus (USB) card reader -- insert the SD card into the USB card reader, then plug the reader into a USB port on your computer.
Download and install a free copy of WiiMedia Savegame Manager. Launch WiiMedia Savegame Manager. The Load SD Card dialog box will open ahead of the program's main menu.
Select your memory card's location from the drop-down menu inside of the Load SD Card dialog box, then click "OK" to load your memory card's saves into WiiMedia Savegame Manger.
Click on the saved game you'd like to work with, inside of the application's left window. Click on WiiMedia Savegame Manager's "Backup" button to save a backup copy of the selected save on to your computer. Use the "Restore" button if you ever need to replace a lost or corrupt copy of the save back onto your SD card.
Click on the "Upload" button to upload the selected save to the WiiNode community. Log into your WiiNode account to upload the save file -- enter your username and password when prompted by the login menu. If you don't already have a WiiNode account, click on the login menu's "Register New Account" option to create a new one.
Click on the WiiMedia Savegame Manager's Definitions heading, and then select the "Download Latest Definitions" option from the menu that appears beneath it. WiiMedia Savegame Manager will take a few minutes to check online for updated game codes, which allows the application to recognize saves from new games.
Select the "Exit" option from the File heading to exit the program.