Sitstart right under The Whey of the Warrior, low traverse to the left up to the left angle, go up in Whey Out West, continue on the slab without using the upper ledge, pass the right and angle and exit in Whey Right, on the right of the starting point.
From the bivouac of Bourron-Marlotte, follow La Route de la Grande Vallée for 200m eand take La Route des Barnolets on the right. The boulder is 250m further, on the right of the path.