This should link your GW account to your ffxiv character and update character info automatically for you. This will also update our roster to include all your job info which is helpful to other team members.

Right click on your name in the upper right corner
Select Dashboard
Go to the Characters tab and select add character
Key in your full character name
Start keying Diablos in the server name and you will get the option to select Diablos FFXIV
Now you will receive pretty detailed instructions on linking your character through Lodestone
Follow those instructions using the code that is displayed for you to copy into your lodestone profile

This should do it for you