I need change my number

Hello,
I need to change the mobile phone that is used to send password reset information. But whenever I want to add another email address or new mobile phone Hotmail asked me to send a code to the mobile phone number currently registered in my account. I no longer live in the US where the number was registered, thus I cannot use the account. What do I do to remove this number? (When I tried to click the remove link Hotmail still asked me to send a confirmation code to the mobile phone number I no longer have). Thanks very much.