Departure: in Google Maps, enter "Rue Ry d'Hez 21/19, 1470 Genappe"; there are always a few parking spaces available at this location.
(S/E) Take trail no. 139 through the Bois de Bérinnes, following the Ry d'Hez.
(1) Leave trail no. 137 (the return trail) on your left. Continue along the Ry d'Hez until you reach a crossroads near the edge of the woods.
(2) Turn left and walk along the edge of the woods (woods on your left, field on your right).
(3) Turn left onto trail no. 137. You will arrive at the intersection with trail no. 139, which you already passed on the way there.
(1) Follow trail no. 139 to the right and return to the car park (S/E).