Got this for you:King's Cross St.Pancras Underground Station Take the Piccadilly Line towards Heathrowor towards Uxbridge or towards Rayners Lane (they are all from the same platform - so don't panic)7 Minutes later .... Arrive at Leicester Square Underground Station.take any exit to be honest... and just follow the tourists ... they will ALL (80%) be travelling in that direction at that time of the day (to the middle of leicester sq), I promise:)