Grand Master Ramos:
To become a Rogue, you need the appropriate level and token. Your level must be at least 20 to qualify to change profession. You also need a token to prove you have passed the Test of the Rogue, as well.
I am satisfied with your level, but it seems that you have not passed the Test of the Rogue. You can only be accepted as a true Rogue when you pass the test. Seek Captain Bezique to take the test. He is at the entrance to the harbor on the west side of the village. To become a Rogue, pass his test and bring back his recommendation.