How can i retrive my pass code to my e-mail if my x-girlfriend changed it?

Yea, so my x-girl frind changed the second answer to my security question on my old e-mail address so i had to create a new one. How can i get back into my old e-mail address?How can i retrive my pass code to my e-mail if my x-girlfriend changed it?Send a mail describing your problem to account-security-help@cc.yahoo-inc.com. Or call Yahoo: 1-408-349-1572, explain to a customer service person what happened.