”משדה התעופה של גווטמלה לאנטיגואה“

Go out of the airport and take bus number 83

ask (in spanish) to be dropped off near the buses that leave for antigua.

 when you get off the bus (in guate after the airport) ask again for directions to the bus to antigua and its like 5 minutes walk from where you get off to where the buses to antigua leave from.

 the bus to antigua is about 45 minuets or an hour and its 4 or 5 Q so dont pay more, they will probably try to ask for it but just give them the 5 and you`ll be fine