You will need a wad manager, such as Multi Mod Manager. Just download the folder and place it in your /apps folder on your SD card.
Then place the wad file in a /wad folder on your SD card (there may already be one).
Launch MMM from the Homebrew Channel and select "load into another ios" and select 249. Then select "install wad" and install your wad.
Your game should now be a channel on your wii menu. Enjoy!