Current Apple ID

My current Apple ID username includes an email address which I no longer have access too. Is there a way to change my Apple ID username so in includes my current email domain. I wish to add the domain of yahoo.com rather, than gmail as my priority email address. I am fearful this will change my account information with negative results. I do not want to loose or, become locked out of my account. Any suggestions or assistance in this matter would be welcomed. In short; I am trying to change my Apple ID to include the ending domain or yahoo.com.