Complex sentence: Giles and Buffy give Xander and Willow a brief introduction to the world of vampires, demons, and slayers, and Willow shows them her computer skills by accessing the city council's plans for Sunnydale's tunnel system.
Split into simpler sentences: Giles and Buffy give Xander and Willow a brief introduction to the world of vampires, demons and Slayers. Willow accesses the city council's plans for Sunnydale's tunnel system.