If you currently have a forced air furnace in the duplex, an a/c unit may not be too expensive, and probably won't require any additional duct work, assuming the furnace is relatively new and a compatible a/c unit is available. 

I've seen it take as long as 6 months and as little as 2 weeks.

There are no specific "minimum requirements," aside from "don't commit fraud" and a human BS test.

I really appreciate iGet a payoff with lenderGet repairs for FHA appraisal passageSee Cashflow with rent vs PITIBuy sub 2 and a note no paymentsLook at a TIC, tenants in common contractSee if @Bill Gulley can expound on the deal possibilities

Even with a garnishment, you have to pay the attorney an up front fee and a percentage of collections, so you would be fortunate to recoup 50%.My advice is to have no ego, anger, or payback when making the decision.  

It would definitely need some work done to make it livable, but it already has a bathroom and a separate exit and I'd like to maximize the space.

The professional's guide to double digit returns, multi-generational wealth, and a worry free retirement." 

Despite the great commission splits at these brokerages, there are still lots of fees in this business just to get and keep your license current, and as James mentioned, you may find it's not worth the time it takes, when that time can be better used sourcing deals. 

As a dealer and a contractor I've often charged a customer to remove them in order to install a new one.

There is a Streamline K $35k and under / no structural changes and a full 203k - anything above $35k that is more encompassing.