Step 1 - get your super duper pilots lizzzence!
Step 2 - Fly short haul legs with other short haul pilots
Step 3 - when short haul is mastered, fly medium haul flights with medium haul pilots and medium haul flight attendants
Step 4 - after decades of acquiring medium haul mastery, you may graduate to the coveted long haul piloting with other long haul masters.

Very simple process