Start: Park in the large car park at the bottom of Roys Peak. The route is fairly straightforward.
(S/E) Cross the fence at the information sign, then tackle the climb and pass a toilet. The path is wide and climbs steadily.
(1) Come to a small enclosure: it's a stele, a good excuse to take a break from the climb. Then resume the uphill path.
(2) Pass a fence marking the entrance to the Roys Peak Nature Reserve. Continue climbing. Reach the ridge ("the view to the north is very clear; it's possible to go back and forth on the ridge").
(3) Continue South. Make a few hairpin bends.
(4) Change sides, and Lac de Wanaka is no longer visible. Continue up and reach the summit ("360° view, especially of Lake Wanaka").
(5) Take the opposite route back down to the car park (S/E).