You can park your car at the North Street Car Park or arrive by bus since there is a bus station just next to the mentioned car park.
(S) Start walking along the aisle until you arrived in front of the Cowdray Castle gate.
(1) Bypass the castle on the right and follow the main path which passes between other buildings.
(2) When you face the "Private" sign, turn left and then right on the next turn. The path passes on the edge of the polo ground.
(3) Turn left and walk downhill. When the path splits, take the one on your right. Then, cross the road and keep going on the main path until you reached the castle again. (1)