Instructions
Take the lift located behind the public auction house in the Valley of Strength to the top floor of Orgrimmar.
Travel to the top of the western flight tower near where you exit the lift.
Wait near the Borean Tundra flight master until the zeppelin arrives. The flight master will announce the zeppelin's arrival in general chat.
Board the zeppelin and wait until it takes you to the Borean Tundra.
Exit the zeppelin once you have reached the Borean Tundra.