Official World Transfer Service Announcement

Using the World Transfer Service, players can move characters on their service accounts to be from one World to another.

Although multiple characters can be transferred from one World to another with a single use of this service, multiple characters from different Worlds cannot be transferred to the same World, nor can multiple characters from a single World be transferred to separate Worlds.

There’s an in-depth explanation post now appearing on the Lodestone, but the long and short of it is that if you fork over $18, you’re pretty much set.
Read more : Official site