Evict them and get a new one as quick as the courts will allow it.

Personally, I have stopped making any loans to owner-occupants at all due as the complexity, cost & risk do not justify the return IMO.If you are dead-set on helping your relative, I think the safest thing to do would be to GIFT them a PART of the down-payment they would need to get a BANK LOAN, with no expectation of getting paid back - you can make an agreement with them that they will pay you back, but know up front that there is probably a greater-than-even chance they will not, and accept that it is really a GIFT and any payments you get back are more than you expect, and "nice to have".

Typically, I'd only suggest one property per LLC if it's a large property (apartment complex) or you have good reason to think there will be issues with the property.

What if it isn't enforceable and the guy knows that and takes you to court?

I have rental that is a condo in a complex of 300 + units.  

I finally did a quit claim because my lawyer advised me it could be another year in the courts and more costs at which point, I'd be just proving a point rather than getting any of my investment back.  

With pictures and supporting statements from witness and police, your tenants could have gone to court to get a restraining order immediately.  

They haven't left, What documentation do I need to bring to court in order to evict these people? 

Daily Court Review houses the list for $19.99 (Harris County)...Along with Storage Auctions and Legal Notices, https://www.dailycourtreview.com/Step 1, you must register...Step 2, well connect with me and I'll give you the run down...If you go on the first Tuesday of every month, bring a lunch.

As I near the final years, I will either be buying considerably larger apartment communities or multiple (2 or 3) complexes per year.