Either the number 1 or number 6 bus from Churchill Square Brighton. These take you along Western Road then into New Church Road, get off at the stop for St.Leonards Gardens on New Church Road. Then walk down St.Leonards Gardens towards the coast, at the BP garage at the end of the road turn right and the entrance to the estate is about 50 yards on the opposite side of the road (See Pic below). Walk down the stairs, cross the road in front of you, turn right and follow it to the end, Monster Studios is in the left hand corner. You could take the 700 bus but it is not as frequent as the No.1 and 6 buses. The 700 bus also goes from Churchill Square and travels along the sea front and stops just before the BP garage.
Travel to Portslade station then walk down Boundary Road towards the cost and at the end of the road turn left and cross the road and the entrance to the estate is about 150 yards.