Co-Management (SCCM+Intune) Hybrid Model to Intune Standalone Migration

Hi

I have requirements where Co-Management (SCCM+Intune) already deployed and now have plan to migrate on Intune Standalone without SCCM. Can anyone please guide or share some documentations as per Microsoft official site they mentioned high level that is not enough to proceed since there are many dependency like on-Prem AD ,GPO etc. How to get started and what are the consideration need to perform. Any down time expected while doing transition.