The method is simple: the outsider must behave as prescribed by his stage, until the power becomes part of him. Until the potion is digested, the bearer is vulnerable: the power is already there, but there is no control over it yet.
The roles of the path are pastoral: the Listener hears what is not told to others, the Shepherd is responsible for those who followed him.
The method long remained the knowledge of the few: church hierarchies were in no hurry to reveal it, and many outsiders ascended blindly, paying for it with their sanity.