How to leave family group

Hello! My name is Ben a fellow member here in the community.

If you are just a member or a child account on the family group, then you wouldn't be able to leave the family group where you are currently added. Only the administrator or parent account can manage a child/member account.

I highly suggest to try recovering the access to the administrator account that you have there in order to manage the family group again.  To be honest, only you the owner of the account can recover the account itself which is why it is important to keep your recovery information up to date. 

If you no longer have access to your recovery information, the last option is to recover your account by filling out the Microsoft account recovery form. You may also follow the guide from the Microsoft support page on the link below which will help you in increasing the chance of recovering your account:

https://support.microsoft.com/en-us/account-billing/help-with-the-microsoft-account-recovery-form-b19c02d1-a782-dee6-93c3-dc8113b20c42

Once done, you may then follow the steps from the Microsoft page below to remove the restrictions and leave the family group:

https://support.microsoft.com/en-us/account-billing/how-to-leave-a-microsoft-family-group-6d806bbb-eb38-a978-10f4-3bbb814ffcc4