There isn’t much to “install” as far as homebrew like WiiMC go. Both WiiBrew and the Complete SoftMOD Guide sum up the process in less than half a page.
Essentially you just need to make sure that you have the HomeBrew Channel v1.0.8+ installed using IOS58. If this is the first time installing WiiMC, you then just unzip the WiiMC 1.1.1 (New Install) and WiiMC Channel Installer 1.6 packages into your SD card’s root directory preserving the folder structure. You should then see a WiiMC entry to install the WiiMC channel in the HomeBrew Channel, run the channel installer once, and then you can delete it after the channel successfully installs.
You should now be able to run WiiMC via the WiiMC channel on your Wii’s Menu or using the WiiMC entry in your HomeBrew Channel.
-Happy Holidays! []D