Croce

From Costaccia top station head left to the wooden cross facing the valley of Livigno. Descend just under it and at first keep to the right above a shoulder with some bigger trees. Avoid the left part which is more steep. Then after the first 200 metres start heading left, picking whichever line looks best. You will then see a path that goes again to the left to a wider forest that you can ski all the way until its end. At the final open fields you will see the lifts of the Costaccia in the bottom and you can decide which one to head to.