The glacier is quite wide with few crevasses (mostly early in the season), bur it's preferable to stay on its right side, as it is also better to stay the right side of the huge undulating terrain that follow the glacier. Under the Refuge de Plaisance, the wide valley narrows into a first constriction where you must cross over onto the left bank (warning : the river hides dangerous potholes under a layer of snow). The slope then widens again into an avalanche deposit zone. Do not follow the river that flows into a waterfall in the Laisonney valley, but cross to the left and follow a summer trail that can be tricky. Finally, a last slope with uncertain snow conditions (generally a lack of snow) leads to the Champagny le Haut cross-country trail. Skate along (while yielding to the Nordic skiers) for 3km until you reach Champagny le Haut. Then a bus will take you to Chamagny-en-Vanoise and the Champagny gondola back to the resort groomed slopes :)