Belgian yeast and pilsner beers don't go together at all, really.
Belgian ALE yeast tends to be fruity and impart strong flavors.
Pilsner LAGER yeast is a completely different kind of yeast that is very clean fermenting and requires low fermentation temperatures to work properly.
I think the Munton's kit comes with a style-incorrect clean ale yeast that will come close to mimicking a lager without requiring the low fermentation temperatures. If I were you, I'd just follow the directions on the kit.