Park along the Rd80 near the Georges Mazurelle specialist hospital.
(S/E) From Acti-Sud, take the D80, which goes around the hospital, and take a small path heading south, 150 metres after the Buissonnets roundabout.
It first crosses the hospital grounds and then continues to the banks of the Yon, opposite the Moulin-Grimaud sewage treatment plant.
(1) Leave the footbridge over the Yon River on your left and follow the river to reach a crossroads.
(2) Continue to the right to pass La Sirmière, then Bel-Air, just after crossing the railway line. You will reach the Bel-Air crossroads.
(3) Leave the direct path to Moulin Neuf on your left and take a small path that leads to the mill, passing under the motorway and then under the railway line.
(4) At Moulin Neuf, cross the Yon river, then immediately turn left onto a blocked path heading north. It joins La Vergne Babouin, passing under the motorway again and on the left bank of the Yon, which you then leave behind.
(5) After La Vergne, continue north, ignore the first path on the left and continue straight ahead to reach La Potinière, after a 90° left turn.
(6) Go around the hamlet to the south and then take a small path. Reach the Yon and cross it to get to the crossroads you passed on the way there.
(2) Turn right and retrace your steps to return to the car park near the specialist hospital (S/E).

thank you
. You are absolutely right; there was a big problem with the route, which did not match the description. I have corrected it, and the route is now 8.23 km long. This is close to your measurement.