Grand Master Ramos:
To become an Elven Knight, you need the appropriate level and token. Your level must be at least 20 to qualify to change profession. You need a token to prove you have passed the Test of the Elven Knight, as well.
I am satisfied with your level, but it seems that you have not passed the Test of the Elven Knight. You can become an Elven knight only by passing the test. To take the Test of the Elven Knight, go to Master Sorius in the town of Gludio. You must pass his test and bring back the Elven Knight Brooch as proof.