You need to take the car park entrance from Tudor Road, Sat Nav postcode HA3 5QB.
Tudor Road is an extension of Cecil Road, the latter being a turning off Headstone Drive.
The nearest station is Harrow and Wealdstone (Bakerloo Line and London Overground). From the front entrance of the station turn left and continue left into Ellen Webb Drive and then into Headstone Drive. Before the railway bridge, turn right into Cecil Road. Prior to the width restrictions (approximately 700 yards) turn right through gates to a parking area at the rear of the school.