After you clear passport control, pick up luggage and pass thru customs, take left. You can either take an inter-terminal connection bus to the domestic terminal, which I think is not that frequent. Or you can take escalator up to the second floor and walk toward 7-Eleven. You pass by it and just walk and walk to the second floor of the domestic termial. Maybe ten to 15 minutes. They have a buggy operating between these terminals. If you wait a while, it'll come and it's free.