On 10-15-95, we did it.
Enter Kahana Valley and park at the state park admin. building. Proceed on the paved road for 20 minutes to where it forks right. Leave the paved road and go left down the jeep road to a dam. Cross the dam and bear left. After 100 feet, there is a clearing on the left side, go in there rather than go right on the road.
Follow the well-defined path that crosses the stream two times. There are occasional ribbons. The path follows a low ridge until the 256' point on the topo map, and then the path becomes choked with uluhe ferns. Then the path clears again and it goes downhill to your left, in a wide path. The trail goes down into the Kawa valley and meanders a little in the jungle, and then it crosses the Kawa stream. It then enters a meadow area and then ascend the side of a ridge via a mud path.
There is a big koa tree at the point where you gained the ridge. Rest there and put on your raincoat to defend against bee sting! Make a right turn up the ridge, and after 5 minutes there is a big beehive inside a dead koa log lying almost across the trail. Don't get near it, the bees are aggressive.
Follow the path on this ridge straight up. Eventually it becomes steep, but the ridge is not narrow and there is plenty of trees to hang onto. It intersects with another ridge coming up from your right, on which there is a curious sphinx-like rock formation. Be sure to go back down the original ridge you came up, rather than the sphinx ridge, because the trail actually appears to go straight down the sphinx ridge.
Keep going some more and you will gain the top of the ridge dividing Kahana and Waikane valleys, at a hump at 1,560 feet. At this point admire the scenery and turn left towards Ohulehule.
The going is not difficult, until you come to 1,800' level, at which point there is a cable to assist you. Unfortunately most of it is more than 30 years old and made of stainless steel (which is why it lasted that long), and it offers very little friction or grip. If you find this is too difficult, TURN BACK. If your fingers slip, you may fall off the sides 1,000 feet ! I measured the topo map and the angle of ascent up the cable is 57 degrees.
There is no need to worry about going back down, however, as surprisingly it's much easier going down holding on to the cables, than hauling yourself up using arm muscles.
I climbed to the top of the cable, and it's 2,000' there. The trail levels off to an easy climb to the top at 2,265. I stopped there at 2,000', but all 4 of my companions got to the top and informed me there is zero view at the top because of 10-feet-tall clidemias all around.
It takes 5-6 hours ONE-WAY up, and 4 hours or so down.
Addendum: HTMC member Patrick Rorie and a friend did Ohulehule on 3/22/97, reaching the top via the route Wing described in less than three hours. Patrick said he did some clearing of the clidemia at the summit so that now there is place to grab a view. He also said he found and briefly followed a trail that led down the southeast ridge, which Stuart Ball calls "the most dangerous on the island."
The HTMC has trail maintenance scheduled for the route on 4/13/97 and a club hike on 5/4/97. While the club hike usually terminates at the 1,560 point Wing mentions, the trail clearing gang may make a push for Ohulehule's summit.