can't sign into hotmail because the phone number on it is old

Pick I don't have any of these when it shows the old number. That takes you to the account recovery form. Fill it from the device and network you normally use for that mailbox and give as much as you can, recent subject lines, people you've emailed, folder names, old passwords. They reply within a day. If it's refused, submit again with more detail, there's no limit. The catch: if two step verification was on, the form won't work and the old number really is the only way, so check the Security page if you're still signed in anywhere.