You now will have the possibility yo leave a guest tenant (https://docs.microsoft.com/en-us/azure/active-directory/b2b/leave-the-organization).
In this how to i will show you how to do this.
- Go to the MyApps portal and login with your Office365 Account
- Go to your profile (right corner) and click the settings icon.
- Below Organizations you will see the tenants listed where you have access to
- Click the organization you want to leave. You will now automatically login to the tenant.
- Click again to the Profile > Settings.
- You can now click “Leave Organization” to leave the tenant. Click “leave” to confirm
- Confirmation of leaving the ticket.