Hi s2allred, 

My best suggestion would be to change the email address on the account with the teacher's email that will be replacing you by following the instructions on this article - https://support.khanacademy.org/hc/en-us/articles/202487580-How-do-I-change-the-email-address-I-use-to-log-in-to-my-account- 

I hope this helps!

Best, Jo