It doesn't sound like you can convert them. I think you can just fill out the email column in the Students and Staff CSV files with school email addresses they may have used in the past to create an apple ID. You can do this at the moment, but a warning will appear in ASM saying the email address is associated with an apple ID and the email address field will just say None.
Is anyone else having issues with their ASM changing users and classes to Manual even though you uploaded them with SFTP. I've had it happen to me twice now which means the next time I go to upload the SFTP file everything will be duplicated. Everything that is listed as Manual will have to be deletd.
