I don't know to tell you the truth.
I do know that the FIRST step you take is to obtain the 747 rating here in the U.S. Evidently it's cheaper and they've found that Americans are better off learning the initial 747 training from other Americans.
After that first two months, you get some time with family, then they ship you off to Japan for 4 more months of their training on initial indoc, and God knows what else it takes 4 months to learn...
But for a starting salary of $92,000 a year, $78,000 while in training, I'll spend an entire day moving the flap lever while chanting a budhist prayer and even try to cross my legs across each other yoga-style... it's all good.