From Takaosanguchi Station 高尾山口駅, you make your way up the small road to the left of the gondola. Within a minute or two, you'll see the entrance for the Inariyama Course to your left.
Along the Inariyama Trail
, you'll mostly be heading along dirt with roots or wood and dirt stairs. You'll come to a few intersections, but they are well marked in English, telling you the correct direction to reach the top of Takao. The ascent should take one hour at a fast pace with no rest, and up to 1.5 hours at a more leisurely pace.
From the top of Takao, there are a handful of trails to pick from to go down, or a gondola or chairlift will take you back to town as well.
This trail is best done on early morning weekdays to avoid the masses from Tokyo that climb Takao on the weekends.