Start out by visiting this website https://account.activedirectory.windowsazure.com/PasswordReset/Register.aspx to enter in your password recovery information.
First you will arrive at this page. Go ahead and sign in with your Lifeline email and email password.
You will then see this page; pretty self-explanatory. Go ahead and set up your phone, email, or both, and then hit finish.
Once you hit the finish button you will be brought to this page. You can close this page out and your work will be complete.
Now that you've added this info the next time you happen to forget your password you can reset it from the home page at portal.office.com