From Dumaguete go up to Valencia via the Dumaguete-Valencia road. Follow that road until it ends. Go right on Taft Street and follow it until the concrete ends (there is a fork in the road before it ends but there is a sign that says "Casaroro Falls" with an arrow). Find a place to park after the concrete ends and walk up about 100 meters, you will see the sign on the left. Cost is 10 pesos/person. Make sure your vehicle's brakes are in proper working order before you head up there!