If you have a small number of properties, you're better off door-knocking or cold-calling *if* you know how to talk to sellers.

For example, when swapping out pex for copper, I put a manifold in with a dedicated line of hot and cold to each faucet/shower/toilet/washer/etc. 

It's typically a good time to do this; not particularly "hot" weather, not yet "cold" (at least not here in Georgia). 

People actually tend to really take care of it and put rugs down, probably b/c it's cold on the feet, but still--it's protected!

Is there a proper way to cold call someone and ask if they are a cash buyer?

Also, zillow shows the market temp as cold.

The situation that would make this conversion the most difficult and expensive is if the branch supply plumbing (hot and cold) for each unit is inter-connected inside the walls and/or slab foundation for each unit.

A great way to find a trustworthy broker is to just cold-call a few in your local area.

Back to my first point, care to share the cold hard numbers that make it a "good price"?

Nevertheless:Current Status:1/Relationships - this is working and also cold calling brokers.2/go to the courthouse and visit eviction court - for this i guess you would need someone there3/direct mail to the owner and drive around neighborhoods - same as above4/no reply so farwish you all the best.