Your character is no longer tied to one job. From today one character can learn all six jobs: Novice, Swordman, Thief, Recruit, Clown and Enchanter.
The weapon in your hand decides your job. Put on another job's weapon and you are that job. You can switch anywhere, as long as you are not in a fight: right-click the weapon in the Character window and choose "Switch to ...", or use the new Jobs window (the Jobs button in the Character window).
Every job has its own base level, job level, stat points and skill points. A job you have just learned starts at level 1 / 1. Nothing is lost when you switch: each job keeps its own progress.
You learn a new job once, at the job NPC under Change Job. You need job level 5 on your current job and the fee. After that, switching to it is free, as often as you like. Novice is free for everyone who left it behind.
Every job remembers what it wore. When you switch, your clothes go into that job's wardrobe and the other job puts on what it wore last. The Jobs window shows all six jobs and their wardrobes, and you can take a piece out of any wardrobe into your bag. Each job also has its own quick bar.
Your character was converted during the maintenance. You keep your job, your levels, your items and your Rufi. Job levels you had earned on other jobs before are kept too. If you were carrying a weapon of another job, that job is now unlocked for you and you received a free weapon for your current job.
Start the launcher to get the update. If the launcher was open, close it and open it again.