I have some experience with this. You need to get a windows util called "Free the Wads". Then download the WAD version closest to your region. I am assuming your running 4.1E (Pal) so look for the WAD that is Pal video.
Put the WAD in the same folder as "Free the Wads" and run it. It's been awhile since I did it so I don't remember the command line switches. Copy the WAD to your SD card into the /wad folder. You need a howbrew app called Wad Installer (I think it's v 1.5). That app goes on the SD card under /apps/Wad_Installer/. Then launch homebrew, the new Wad Installer will be there. Select IOS 249 then select the modded WAD. It takes a few minutes to install. If all went ok you will have the app installed on the Wii dektop. Good luck.