Follow the ski du fond track north west, until you come to a path through the trees heading west follow this it briefly comes back on to the ski du fond track. Follow the torrent Du Creuzet south you stay to the valley floor until it steepens with a tight gorge, turn east before the gorge and climb the steepening slopes, then turn south again on easy angle terrain,follow this and you should see the North facing face up to the Crete de Lenion,climb this to the ridge. (You can head east a small way to see the Ancient Fortde Lenion)
Ski back down the same way. You could also head west early and drop into the valley floor higher up and ski the gorge you saw on the way up.