Hello Amor! After you have gone through the security checkpoint. You can take the plane train that will get you swiftly from the domestic terminal to the international terminal.
The have a very fast underground tram system. Signs overhead with arrows and tram access stairs marked as well down each concourse. I have not been out that way in a while but I do remember it was both marked and convenient.
You really dont want the walking option.
Catch the under ground transportation, or walk.
You'll need to take the plane train, or walk, to the international terminal.
I would ask a Delta employee when you arrive at the airport, they'll be able to show you where you need to go.
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