This is a amazing line, and if you have spent any time in Briançon you will have looked up at it and wanted to ski it. It's a long day and you have a bit of a flat skin to get back to the parking at the end of the route but it's worth it.
From the parking at Boucher follow the GR50 north. This is a wide fire road, at the first long bend west take the track SW. It climbs in the tress and leads to the ridge and the Serre des Hieres.
Follow the ridge to the top near the Croix de la Salcette, very often this lower section has poor or little snow so you sometimes need to walk this section carrying your skis. From the Croix, traverse in to the face next to the Crête des Lanciers. Climb this face, and be aware that this is a steep face - and south east facing - so it will have the sun on it early. It gets very steep as it comes to a small col/breach at the top.
Ski the opposite side of the col - it's steep for the first few turns. Head north and then pick the best line through some rocks (it's normally obvious which are the clean lines). Once through the steeper stuff, roughly follow the Combe Brune. This leads you back down to the GR50, care is needed getting back on to the GR fire road as it can have a lot of rocks. Once on the GR50 skin/pole back south to the parking, this is a long track but easy and flat.