[Solved] How can we combine emails for a student using Google Classroom?

Hello,

My student has been playing Classcraft all year. I have finally started using the iPads and created a Google Classroom for the students to use. He had used his Google email which is different from his school assigned smail account which is also through google. When he tried to update the email Classcraft said his email was already in the system. When I combined their Google Classroom student emails with ClassCraft using "create new students", Classcraft did not combine his information with his established character creating an entirely new avatar that does not have all his bells and whistles. I am trying to manually combine the two accounts and do not see a way to do this. I have 22 classes and this is not the only student that has this problem. How can we fix it please?

Edit: Students who had not added yahoo or gmail addresses had no trouble getting their established Classcraft accounts and Google Classroom accounts to combine. No email attached to ClassCraft, then no trouble.