Is it possible to change secondary profession?

Someone told me you can change your secondary profession at some point in the game, but I haven't found a way to do that yet. Is it possible?

Yes. After you reach Droknar's Forge, once of the NPCs will give you a quest that sends you back to the desert, three outposts in particular to 'talk to the Ghosts' - the quests that these ghosts will offer you will allow you to change your secondary profession.

LOL. I was wondering why when I returned the woman asked "You didn't actually talk to anyone at the locations, did you?" Oops... Ah well, I was happy with my Mesmer/Warrior anyway .