Here is what you need to do...
Extract the folder call snaking into my games\LegendaryHeroes\Mods

Then make sure the xml file is in the folder

Start FE: LH and ensure that you have the use mods option selected

After that you must start a NEW game and the mod is available for you as you play.
If it is not working after this point, I would need to see screenshots as to what is not working, because I'm at a loss of what is broken.