I would approach the tenant extremely professionally and be upfront with them about the situation and give them a chance to explain what happened.

I try to explain its an old building. 

Explain to them that you did the 6 month lease the first time because of the timing. 

Here's a government site explaining evictions: https://ota.dc.gov/page/guide-...If the Tenant is willing to sign a waiver, then that indicates they are willing to leave.

___Now before all you out of state investors and Realtors start jumping down my throat, let me explain.

Try understanding them first then you can explain your side.

I needed clarification in a real estate purchase and sale agreement on a wholesale Offer to purchase agreement.  1) The correct way to explain to the seller whether this is negotiable or not 2) if negotiable who negotiates it  ( buyers agent /seller agent in case the best use case is wholesale ( realtor to represent the wholesaler) What is the true logic behind the non-refundable due diligence, in wholesale transactions if the wholesaler is not taking title to the property how is it reflected in the contract, does it get subtracted from the purchase price or not?

Let's just hope that if she was not locked that it was explained to her in-depth.

Make sure it explicitly explains the process for termination if you are unhappy with their services, but especially if they violate the terms of your agreement.3.

Make sure it explicitly explains the process for termination if you are unhappy with their services, but especially if they violate the terms of your agreement.3.