GAOH is right.. you just say '안녕하세요' that's it.. I just want add more.. 1. good morning. . : 좋은 아침입니다.(good morning), 잘 잤어요(do you sleep well?), 아침 드셨어요?(did you eat your breakfast?_it rare used), 일어 나셨어요?(did you wake up?_it used you sleep the same place) 안녕하세요..is 'hi' ^^ you can use anytime ^^

You can say 좋은 아침~ when you say hello to your close people in morning. If you say hello to an elder person, you should say 좋은 아침입니다~~or 좋은 아침이예요~ such things..

there is a way to say good morning but every one just say 안녕하세요 usually