The star will be found in a yellow box near the freezing pond, which is the one that has waters that drain your health just for being in it. At the beginning, follow the path to your right and go for the tree that warps you to the freezing pond. You will want to use the Spindrift that’s just in the water on the far side of the section with the moving mounds of snow. If you want to wait a tiny bit for the Spindrift to come out of the water, you can, as it shouldn’t affect whether you can reach the ledge or not. As soon as you jump off the Spindrift, hold forward and you should get on the ledge, where you will see two yellow boxes. The left one contains the star.
If you wish for another method of getting on the ledge with the yellow box containing the star, in case you messed up with the Spindrift, then it is possible to Triple Jump and dive at a certain location. After taking the warp, you should see the steep slope right behind the signpost that’s next to the tree. When looking at the slope, the spot to the right of the tree is the ideal location for performing the Triple Jump. Make sure the second jump is on solid ground, then try to get the third jump a good ways up the slope if you can. Once you get on the above ledge, you can simply run over to the box with the star.