Skimming trough half the book time and again I didn't find it: under what circumstances how (ruleswise) are heroes created?
See Advancement on p215 of Beast: The Primordial.
When a Hero is created as a recurring antagonist in a chronicle or is being built to face down a group of experienced Beasts, the Storyteller should hand him appropriate Attributes, Skills, and other assets as necessary to challenge the player characters.
While keeping in mind several pointers of p206 with regards to Heroic Traits (like Hard to Kill, having Integrity, followers, Gifts...). So you can stat them out using normal character creation rules (looking at the example heroes here)or you have a rough concept and linked some fitting Gifts to that.
If it's more related to the "waking up" check p201-203.
Especially the following section:
In game terms, the Heroes that stalk Beasts tend to have low Integrity ratings — their souls are weak and ill-defined. Being a Hero is, like being a Beast, something that a person is born with.