Not the most efficient way, but it woks for them.  

Do this ASAP or else you’re at risk for having the payment for next month go to the former owner (hopefully you had a clause in the contract to ensure they would forward you the payment if this happened).

When talking to your step dad and mom, ensure they are okay with you putting a 'lien' on the property.

Since there are thousands of numbers, I want to be as efficient and effective as possible so I can go through many phone calls. 

How can I utilize this equity to efficiently purchase more rental properties? 

I just finished rehabbing an SFR into an energy efficient home for airbnb with gas tankless water heater to lower costs.. 

It's our full time job and I know it's not as "efficient" as it could be but it's very stress free only dealing with ourselves and no one else.

Working with a reliable and resourceful agent will not only save you time, but will hopefully ensure a smooth transaction as opposed to the headaches of doing your first deal on your own.

There are a couple avenues you can take to ensure owner occupancy.

There are several HML I know that can move very quickly and allows borrowers to only put down 10% to 20% and will finance 100% of the rehab costs on 12 to 24 month loans.I would highly recommend shopping around various HML in this situation to ensure you're getting the best rates and leverage.