Walk out of the airport, walk over the crosswalk to the parking lot and continue to the building with a brown roof about 100 meters in the distance. On the other side of this building is a bus stop where the 138 will pass heading to San Salvador. The last microbus is at 5:30 pm. Tell the driver to drop you off in Comalapa. From here, get off the bus and ask for a local where you need to go to switch to the 187 going to La Libertad. You will need to get to the other highway going to La Libertad. Once in La Libertad take bus 80. This bus goes back and forth between Sunzal and La Libertad passing El Tunco and runs every 15 to 20 minutes from 4:30 am -6pm. The cost is $ 0.25. Alternately, you can take the 192, 192A, 192B which passes La Libertad and continues on to Zonte. tell the driver to drop you off at conchalio beach km 37