Dark elf - Light Elf

Now apparently you can choose a subclass light-elf being dark-elf in Ertheya. But one question, my main is Iss Sword Muse and my dualclass Arcana Lord, but I want to change the dual to Wynn Spectral Master.



This is right? or sublass not include dualclass? Is there any way to do it without resetting the dual and start from 0?