It's fairly easy, just copy the file to the location I specified on the thread. It's important that you delete any previous saves before doing so. good luck!
here's a great tutorial for you
How-To Backup, Swap, and Update Your Wii Game Saves - The Tech Game
"Copying Games from your Computer to the Wii
Let's reverse the process now and put that copy of the Pikmin game save onto the Wii. We have the game save backup in the proper directory for the game, \private\wii\title\R9IE\, and all we have to do is put the SD card back into the Wii navigate to Wii Options -> Data Management -> Save Data -> SD Card. Select the game save you want, click Copy, and you're in business..."