I. Mule?s Errand
When your character reaches Level 15, go back to Flaris (the main town) and talk to Leily. She will ask you what job you wish to become, so select Magician. Now you will have to go an speak with Mule, who is northeast from where you are now, near the mountain and river. He will ask for you to go get a book from a pupil of his, Marche.
Ask Marche about the book and she will hand it over. Once you?ve received the book in your inventory, travel back to Mule.

II. Torn Pages
Mule now asks you to go get the Wand Making book from Marche. So go back to her... Yes, again.

Ask Marche about the book again. She says that she had fallen asleep under a tree and the Demians had ripped out 10 pages from the book. Regular Demians (the orange-haired ones) can be found in the Demian village. It can easily be spotted because you will see a bridge in the map.

II. Reparing the Book
After getting the 10 pages go back to Marche in Flaris. She will then repair the book and hand it over to you. Get the book, and go talk to Mule. Mule takes the book from you, gives you a complimentary wand, and finally makes you a Magician. Congratulations!