Approach :

1st day go up to the Robert Blanc hut (2750m).  Parking Chalet des Lanchettes (1975m.)

Route

From the hut either descend 80m and traverse towards and across a little rock ridge, or descend 200m to pass underneath this ridge
From there go straight up the face, keeping mainly to the true right bank, either until a dome of snow or until the shoulder of the Aig du Glaciers, (a better view.)

From here, and depending on the snow conditions, it is possible to reach the summit by a west facing gully.  

Descent

Two possibilities :
1)  by the true right bank of the glacier.
Find the best line through the crevasses, then go down between  the moraine and the ridge coming from the Pointe des Lanchettes.  Traverse to the right underneath this ridge to pass directly above the hut and bypass some rock bands.  By going to the left, gain the Lanchettes stream, which you then follow.  

2) By the true left bank of the glacier and the Cabottes ridge
Once on the face go to the left along by the Cabottes ridge, then at 3050m traverse to the left to gain the slopes which come from the Col de la Seigne and continue down the little valley “des Cabottes”.  One can also cross the Cabottes ridge higher up at about 3150m (more exposed and steeper.)
Depending on the snow conditions, it may be possible to descend to the right of the Cabottes ridge and so avoid the traverse at 3050m.
It is recommended to work out the preferred descent before leaving the hut.