On your right, you will see a footpath leading into the forest and then going upwards through steep bends.
At the first crossroads, turn right, then 50 metres further on, turn left along a steep footpath that continues to go up through the forest.
You then arrive at the wide Rosière footpath, which you should follow as far as the Route du Belvédère.
You then come to a bend at the Zénith accommodation centre (the seventh bend you come to on the way up from Courchevel 1650).
You can also go to the centre of Courchevel Moriond, as you did on the way out, by following the Belvédère button lift, by ski bus or on foot along the road.