The standard route is from the Otira valley - just after the footbridge head up on faint trails onto the grassy ridge with clear views to the north - then scramble up Warnocks bluffs (clearly visible from the road and cairned) - be careful here and pay close attention so you are able to find the route down on the return if cloud comes in.

From here it's straightforward to the summit (it's tempting to head out on to the ridge on the south side, but this becomes slow going higher up).

From the summit there's also the option of heading south along the airy ridge half-way towards Mt Rolleston High Peak and dropping west just after pt 1860, then sidling across and up to Waimak col, then out via the Waimak (or the more remote Rolleston River track).