Limousine bus to Haneda

We are staying at the Citadines Shinjuku on Yasukuni Dori about a kilometre from Shinjuku station: we fly out of Haneda at 9.45am tomorrow morning so need to be there about 2 hours before (although we have already checked in). We're flying to London on BA. We have booked the Limousine bus for 6.30am, arriving at 7.10am at the international terminal. We have small luggage so we are thinking of just walking to catch the bus at Shinjuku, is the bus stop at Shinjuku easy enough to find? Thanks in advance