Easier to get to than before (no barbed wire to negotiate) approached by a well used path with handy new stile and sign posts at the top.
Following the path that accompanies a narrow line of trees on the Wilkiston road out of Ratho head to the top of the hill past a rope swing, very popular with dog walkers (not the rope swing...or at least i think not) If you like you can get the number 20 lothian bus from Slateford (Chesser) to Ratho then after your neolithic detour go along the canal for cake and coffee at the brilliantly odd international climbing centre.
If you are visiting Jupiter Art Land then you can walk stealthily out through the farm at the back of the estate through Bonnington mains, cross the road and head towards Ratho. Then take sign posted path on the right to tree topped Tomain hill opposite the horribly vast water filled quarry on the other side of the road.
The easiest way (but not most direct) to get here is a walk up through Centre Parcs, follow signs for activity centre, then follow signs for the horse riding centre, short walk up the steep hill. You can then follow the right of way down an incline through the trees to the South east corner of the plantation where you cross a stile to a field. Now next bit is not a path so keep to the edge and dont walk on the crops, follow the field along the plantation going due west north west and you will get to the stones.
On your way back through centre parcs you could have a shot on the canyon water slide or the flumes (if they are open) just remember your swimming gear.