How To Update Your Microsoft Profile?
First, the user should Change display name. For this, you should Sign in to the Your info page on the Microsoft account website. Then under your name, you need to choose Edit name. If incase, there’s no name listed, then you should choose Add name. At last, you should enter the name which you want, and then just write the CAPTCHA and choose Save option.

And to change a birth date on Microsoft account, then you should go to www.office.com/setup365 and then just sign in to your MS account. After this, you should choose Your info. Then in Your info page, you need to choose Edit date of birth. At last, you should make the changes and then choose Save option.