Drive your vehicle to the top of the Sainte-Foy-Tarentaise resort. Take the track towards Le Monal (it has a few water crossings but is perfectly passable by car) and you will arrive at the Coleurs car park.
(S/E) From the car park, head towards Le Monal via the Via Alpina.
(1) Cross the hamlet of L'Échaillon and you will reach Le Monal.
(2) At Le Monal, where there is a refuge if needed, cross the hamlet and climb up to your right. At the first fork, turn left towards Le Clou, where you will join a wide path.
(3) Follow it to the left and pass below the Barrage du Clou dam to reach the hamlet of Le Clou.
(4) At Le Clou, take the path on the left which climbs quite steeply towards Lac du Clou.
(5) At the lake, follow the path that continues to the left and climbs towards the Col de L'Aiguille (there are several paths, but this one is easy to find).
(6) At the pass, descend along the ski slopes towards the chairlifts on the left. Pass under the Télésiège de l'Aiguille twice and you will reach the hamlet of Arpettaz.
(7) Continue along the track and then the path that branches off to the left, passing under the Arpettaz chairlift, towards Le Monal (which will now be clearly signposted). The path continues through the woods.
(8) At the crossroads, a sign indicates the way back to the Coleurs car park (S/E).