Cover the slow cooker with the lid. Cook until the chicken is tender on low for 4 to 5 hours or on high for 2 to 3 hours.
While the chicken is still warm, transfer it to a cutting board or large plate and use 2 forks to shred the meat.
Divide the meat between the tortillas. Top with guacamole, pico de gallo, and fresh cilantro. Serve immediately.