If you can get your luggage checked through to your final destination (which they should be able to do for you), you just need to exit the domestic arrival area downstairs and go on the elevator to the departures hall upstairs. The security check is common for both domestic and international departures (go right after security to get to the international side). This should take you approximately 20 minutes from gate to gate if there are no long queues in security, which I doubt there will be.
Snacky