Once you complete the tutorial quest, you will be able to freely switch between your main class and your subclass (30 minute cooldown). You may switch back to your main class by following the steps below:

1. Complete the tutorial quest "Subclass" in your Quest window (Q), if you haven't already. Please note that you can only complete this quest while on your subclass, and this is only necessary for the first time you switch.
2. Go to the Orca Area in Infinite Corridor near Guild Union and enter the subclass switch area.
3. Remove all of your equipped battle items in your Equip window (E).
4. Enter the portal and confirm your selection.