Changing your date of birth (DOB) in a Microsoft account typically requires administrative access, especially if your account is set up as a child account. Since you mentioned that you do not have access to an admin account and cannot remove yourself from the family group, your options are limited. Here are a few steps you might consider:
- Contact the Family Group Admin: If possible, reach out to the admin of your family group and request them to change your DOB for you.
- Microsoft Support: If you cannot contact the admin, consider reaching out to Microsoft Support for assistance. They may have procedures in place for situations like yours, especially if you can verify your identity as an adult.
- Create a New Account: If all else fails, you might need to create a new Microsoft account with the correct DOB and start fresh, but this would mean losing access to any content associated with your current account.
Unfortunately, without admin access or the ability to remove yourself from the family group, changing your DOB directly is not feasible.