From the parking at Le Laus follow the road south (towards the Col d’Izoard) until it is blocked off. On the left, there should be a ski de fond track, follow this into the valley on the left (south-east). From the hut after a long straight section it bears left and climbs steadily. At around 2052m you should find a small bridge on the right of the track. Take it and then work your way south- west through the trees. As the trees thin out you will see L’Arpelin east face on your right. Continue going south into a small bowl. Cote belle should be straight in front of you, there is an open face on the right and an hourglass shaped face on the left, climb the open one to a small ridge, from here it is sometimes possible to climb the ridge and another face to the summit, or descend from the ridge.
If descending from the ridge you can go back down the open slope or traverse in to the hourglass shaped one. From the summit its straight in to the hourglass shaped one, at the bottom of both follow your tacks back to the parking.