To hike the Vulcano Villarica you have to book with a travel agency (even when it's not a technical different one). Anyway, there are lots of travel agencys in Pucon, but please, DO NOT choose AGENCIA
FLORENCIA at Calle O'Higgins because they are terrible. No briefing about the trek, no, really no information about the environment or the vulcano, damaged and very old equipment, wet ...