Here is description of the steps :
1. disembark the plane
2. go through US immigration.
3. pick up checked bags at the baggage belt
4. go through US customs
5. re-check bags at American Airlines connecting flights counter, located immediately after customs.
6. go to the third floor of T8 and obtain a boarding pass if they do not have one already issued by the airline. They can do that either from the self-service kiosks or from AA check-in counters.
7. go through security and look for the gate number for the flight to Miami.
Here is description of the