Park by the war memorial in Reay (across the road from the church). Follow the Borlum circuits signs up past Borlum house (the large white one), when you reach the forest track turn left until you almost reach a gate. Just before the gate on the left hand side is a corner of an old stone wall, turn left there and follow the faint  track up onto Borlum Rock. There are some archeological remains on the hill. Come back down onto the forest track, you can either turn left and go further into Limekiln forest, turn right and return the way you have come or turn right and instead of turning right to return past Borlum House keep on the track which will bring you out about 800 m to the west of where you parked, follow the road back to the car.