If I have to sell, most likely will be moved towards a 1031 exchange.

Money in exchange for equity, HELOC is generally easier to get, it's like a credit card, use it as you wish or draw on it as needed.

@Andy YoungBefore selling this property, consider 1031 exchange to defer paying taxes.

@Edward Fedorovich Another option to consider on the 1031 route is selling multiple properties and treating them as a single exchange and using the total proceeds to purchase replacement property/properties.

In return, they would theoretically agree to sell us the house when they're ready.Mom & sons continue to live there until they decide to sell (likely soon to pay for college) or until the divorce forces the sale.Once they are ready to sell, we buy it at a discount & flip it.Alternatively, maybe we buy out the husband's equity in exchange for part ownership in the property, then buy out the wife's portion when they are ready to move. 

This will include a GOOD hard money lender (or a few), an experienced Title person who knows the ins and outs of investor deals, and can offer investor discounts on title fees, a 1031 exchanger (the title person should have a good connection there), and a few contractors and/or subs for rehab work.

@Zocky Zhang, As everyone said, you can't exchange from investment property into your primary residence. 

Yesterday I did a Cash for Keys exchange, changed the locks, and took possession.Walking through the house, I’m trying to decide what to do with it.  

And be precise. 10K escrow holdback to be released only upon buyer inspection that the property has been delivered in broom swept and vacant condition with no additional damages since initial inspection of property.

Although we had e-mail exchanges about his situation (he said he is trying and that he has some kind of job working from home), I have not officially sent him a 10-day notice but I am considering doing it this week.