I do NOT have enough knowledge or experience in this arena to provide specific “how to” accomplish this, or even to provide specific”proof” of my position.  

It all comes down to inventory.

What would I need to do to structure the note in order to have a note buyer come in and buy the note or buy a partial enough to pay off the 215k at closing and still have some difference coming to me or the note revert back to me after the partial was paid for. 

If you just want to make some quick cash so you can supplement your retirement, then sell it and relax.

Go to a couple of real estate investor meetups and make connections.

Stock market-  it’s time for a 40 to 50% dive.Whether any or all of these come to fruition as an issue, just one of them would have a significant impact on REI.

Once you find a good property and all the numbers make sense - pull the trigger.

They're currently renting in Denver under only the guy's name but since the girlfriend is pregnant, they need to move to a bigger place.

We would need to know your current operating expenses (and rent) to be able to provide any suggestions.

Welcome to BiggerPockets, Joshua!