If you’re using the Azure AD Connect tool (or Azure AD Sync Service) to synchronize you’re on premise Active Directory with the Azure Active Directory, you can use this script from TechNet to trigger a full password synchronization
You need to replace the following
- fabrikam.com
- aaddocteam.onmicrosoft.com – AAD
with the names of the connectors in your own environment. This can be found in the Synchronization Service Manager (installed when you install Azure AD Connect)