Start in Poolewe, from the car park by the school near the bridge over the Ewe. Head up the single-track road with the river on your right. Go through the gate, then the track heads away from the river and up into woodland. At the Letterewe Estate gate cross the stile and continue to the next fork. Turn left here to Kernsary Estate, with views of Loch Maree and Beinn Eighe to the south. Follow the track to the next gate, go through and cross the wooden bridge. Continue along the track and you'll see Loch Kernsary on your left. At the next fork, turn left over the bridge and pass Kernsary Cottage on the right.
Beyond the cottage, go through the gate and immediately head left down towards the burn, where the ground may be boggy. There's no path here, but cross the wooden footbridge and continue straight on, past the piles of stones on your left. Cross the stile, and the path follows the length of Loch Kernsary. At the head of the loch, the path climbs to give you views down to Poolewe. Follow the path down till it eventually takes you to the main road. Turn left and follow the road back to the car park.