House Extension into an ADU

[Ward Gavin]

I recently purchased a SFH with a fully permitted extension (not an attached ADU). The extension has its own front door, garage, kitchen, bedrooms and bath however it does not have its own address. The two halves do not have any shared space. Can anybody provide some insight on how to legally convert this into an ADU or Duplex with it's own address or recommend an ADU professional to walk through the process?

Front Half: 2 bed / 1 bath / 1 car garage / ~1000sqft

Back Half: 3 bed / 2 bath / 2 car garage / ~1500sqft