Approach

In Winter/Spring (Skis)
From the foot of the Champex chairlift get to the ski de fond behind the lake, then at a hairpin bend, take the footpath for the "Combe d’Orny", signposted.  Depending on the snow cover, it is best to go up before the end of the path to gain a large open space under the SE slopes of the Breya, then reach the lower part of the N Combe (cwm) of the Chatelet, by a horizontal traverse. Go up the Combe d'Orny, taking care to stay to the left on the way up, to avoid re-descending about 50m to the foot of the N face.

In Summer from the Orny or the Trient huts (on foot).
From the Orny hut, (or Trient hut,) go onto the glacier d'Orny and traverse this to the foot of the N face.

Route

Overcome the bergshrund, and climb the N face.  From the col at the top of the face, reach the summit by some rocks and then snow.  

Descent (skis)

It is possible to ski from the summit and then climb back up some rocks for 10m. From the col ski the face (S5). It is possible to return by climb up to the col d'Arpette, (behind the Ormy hut,) cross it, and go into the Arpette valley.

Descent (on foot)

Go down the normal route, i.e. the W ridge and then the N flank back onto the glacier d'Orny.