Start from the Reelig Glen car park (NH558431). To get there, take the A862 from Inverness towards Beauly, then follow the "woodland walks" signs after a few miles near Moniack Castle/Winery.
Take the NW path from the car park. The path zig-zags up a hill then after a further 100m you will come to a viewpoint.
From the direction sign at the viewpoint, look for a dead tree stump about 15 feet high, 40p downhill on 10 degrees. Go to the stump and find the box hidden behind it at ground level.