In reply to paulmo101:
From A+E you head on a bearing 330 which takes you past the left side of a square block on the horizon. Down for a bit before turning slight left on 300 down a rocky gully. Then either go right down a scree gully with trods crossing it to the road near the N ridge, or carry on to come out on the road a bit more towards Ogwen Cottage.
I did it last weekend on a friend's Paddy Buckley and it's a pretty tricky descent