Final Fantasy XIV posts the full instructions for Stormblood early access

Oh, the places you'll go.
Whatever you want to accomplish in Final Fantasy XIV, you had best do so before the servers go down for maintenance for 24 hours on June 15th. That’s a fair bit before Stormblood releases, but it’s also timed to coincide with early access for Stormblood pre-orders starting on June 16th. So what takes place during early access? Why, the first wave of players getting into the expansion, naturally. So you’d better be prepared, which means that it’s a good thing a full breakdown is available on the official site.

Players will be able to access all of the expansion starting on June 16th with no restrictions on content or discussing content, although it’s considered polite to refrain from spoilers. You will need to finish the MSQ through Heavensward to take part in most of the Stormblood content, although any character at level 50 or above will be able to access Red Mage and Samurai. Your early access code will also enable play of the game through June 23rd, at which point you’ll need to register the full expansion code to continue playing. So start counting down; you’ve got about two weeks left to get ready.