On the plain of Obere Stafel hike horizontally about 50 m west, where you find a faint path which leads intermittently to Fleschsee. From the knoll before the lake (2438 m) you can overlook the wide slope between Wannihorn and Fleschhorn and memorise the upcoming ascent. To the right (west) of some compact rocky ledges in the centre of the slope a hardly distinctive rib can be made out (roughly in the fall line of P. 2837 on Wannihorn). On this rib there is a faint path with a few cairns now and then. To reach the rib you walk around Fleschsee by the eastern end. At ca. 2600 m the faint path disappears. Now traverse east and south-east (cairns now and then) up to Halbelfjoch (nameless on the map, east of P. 2756) and continue on rocky ledges (easy climbing) to the ridge east of P. 2817. Follow the ridge line eastwards until on a good ledge you can descend to the depression full of scree to the right (cairn on the ridge). Now ascend east-south-east in this depression with scree and névés to a distinctive breach, which is visible from the ridge. A faint path and cairns show the way through this breach to a surprising plateau with rubble (ca. 2990 m). Making an arch to the east via P. 3018 you reach another scree plateau. Ascend north, then east through a steep, slippery slope with earthy schist towards P. 3156 (very precarious with snow or ice). Now follow the north ridge to the summit. Rocky structures can be overcome by easy climbing (passages up to II) slightly on the right of the ridge line.

Descend on the same route. Below Halbelfjoch make sure to traverse far enough west to reach the rib below Wannihorn. If you descend too early, you will find yourself on dangerous slopes.