Does your wii is connect to internet?
If not you'll need ios from NUSD and pack to wad put in the root of your sd card
2.Run NUS Downloader. Check Pack -> wad at the bottom. It will say '-NUS-[v].wad'
We need to download some files now.
* NUS (IOS > IOS 15 > v257 &WAD)
* NUS (IOS > IOS 15 > v523 &WAD)
* NUS (IOS > IOS 36 > v3351 &WAD)
The final thing to download is the System menu IOS. As we will be using 4.2, the IOS we need is IOS70.
First Uncheck 'Pack -> Wad'. The box will become gray and empty.
* NUS (IOS > IOS70 > v6687)
Once you downloaded them all, go to the folder where you extracted the NUS downloader and you will see 4 new folders. Copy the wad in each folder to the SD card (NOT to the wad folder).
Open the new folder in the folder of the NUS downloader and copy everything in it. Go to your SD card and create a new folder called 00000001. In that folder, create another folder called 00000046. In this folder, create yet another folder called v6687. Paste the things you copied here.