Since Lykaon doesn`t come with an installer then all you should have to do is unzip the download and then copy and paste the folder Lykaon into your Witcher 2\UserContent folder
If still no mod shows up then try opening the Documents\Witcher 2\Config folder and right click the the UserContent ini file and select edit and type this in or copy and paste it .
[Packages]
Mount=Lykaon
Now retry the game and select new game and see if it shows up .