The first part is literally a reading of the Popol Vuh (because some of my students say it helps them) and the second part (starting at 1:41:57) is a commentary focusing on themes of:
1. Xibalba (Place of Fright/Underworld)
2. death (how the Maya may have conceptualized it)
3. rebirth (or how the Maya conceptualized the Hero Twins defeating death or the Lords of the Underworld.