I climbed this mountain with Mark several years ago, but neither of us could find any evidence. No photos in my collection, and no notes in Mark's notebook. Just what Mark called a "shared hallucination" of us both having been there.
Finally, I've remedied this! Mark led an Alpine Club trip up Lawrence Grassi not that long after we (may or may not have) climbed it, so Kevin and I decided to climb it while Mark was out of town. Cheryl, Kevin's sister, decided she'd like to join us.
We parked at the parking lot at the bottom of Ha-Ling, walked up to the canal, crossed over the bridge, and walked down the other side of the canal for a while. It used to be harder to see the start of the trail leading to Lawrence Grassi, but it's very easy now. Walk through the jumble of big rocks that block the "road", and within 50-60m of passing the jumble, you'll see a trail leading into the forest on the left. There is a cairn there, and an attempt at building an arrow out of wood. All that's missing is a flashing neon sign!
Follow the trail, making sure you don't end up on the right-hand side of the gully somehow. The trail eventually cuts up the side of the gully to the left (well cairned). The trail zig-zags steeply up toward the tree-line. Once you're out of the trees the trail is mostly still will marked/worn, except where it goes across bare slab. In most of these cases it is either well cairned, or follows an obvious weakness or feature.
Once you're out of the trees, you can pretty well see to the summit. It looks like the block at the top is the summit, but it's actually lower than the top of the ridge you walk up (which is cairned). From below, you can see the skinny part of the ridge which isn't really that skinny once you're up close to it. Above this skinny part, the ridge steepens somewhat, and is covered with more loose crap than the lower parts for some reason (maybe a lot of people turn around at the skinny spot?). The summit is only a couple hundred meters further up the ridge from this point.
While walking up toward the skinny spot, I noticed that further north there was a squall blowing in, bringing with it what appeared to be snow. In a couple minutes I was proved wrong. It wasn't snow, but graupel, and a nice strong wind to blast it into the sides of our faces, into our ears, etc. It was a very pleasant time, and we were all sorely disappointed when the squall moved on.
Once we got to the top, I climbed up onto the block next to the summit just because it was there. It's pretty airy on the steep side, but worth the extra two minutes.