Let them know despite repeated attempts to collect the money, it is not forthcoming and that you will be starting the eviction process for non-payment of rent...then hire an attorney who specializes in evictions and get the process started.

Tell ya what, once you've hit journey in just 2 trades I will let you attempt to talk down to me. 

Tenant agree that the reletting charge is a reasonable estimate of Landlord’s damages and that the charge is due whether or not Landlord’s reletting attempts succeed.

@Maciej G in my opinion you have gone above and beyond with attempting to mitigate the situation.

I've made several attempts to personally deliver a five-day notice but haven't been successful.

Have you attempted to speak with the neighbors to try and address it head on with them?

I explain they will have difficulty Renting a quality unit, that I will ding their credit, that I will attempt to garnish their future income to recover what they owe.

This scheme had been attempted, and it was shot down in court.

I attempt to study what you mentioned in your earlier response—60% bonus depreciation upfront, 40% over the course of 15 years. 

The people advising to put properties into LLCs and not the loan, and add additionally insured to their policies have no idea what they're doing.The fact is everyone doing this in an attempt to limit their liability, is actually doing the opposite and greatly increasing their liability.