You want to avoid a lawsuit, and a demand letter shows you mean business but concurrently allows the seller an opportunity to remedy the problem before it escalates.  

The geologist and toxicologist hired by the plant for ground and air sampling has assured me that the property is not in the contaminated area (I have these contacts because my current residence a block over has vapors coming in through the foundation and remediation in progress). 

Obviously we will see how this plays out, but a lease is a legal contract and unilateral changes to a contract are not generally a judicial remedy. 

Hi Biggerpockets,“What remedies to expect/use on wholesalers that keep the ‘good faith escrow’ and don’t return it?”

Full scope rehab included new kitchen, 2 new bathrooms, new flooring throughout, all new windows, new exterior paint, and significant mold remediation as well as several serious deferred maintenance items.

Finished attic, unfinished basement, hardwood floors and steam heat... the images of all the rooms seam to be in good condition, nothing paint couldn't remedy.

And it sounds like remediation for old petro tanks too!

The MTM in theory gives you flexibility, but if the tenant goes sour on you then the only remedy is still the court system.

For most situations in Oklahoma, you'll want to issue at least a 5 day notice in writing to "remedy the situation."

I would not choose to use this contractor again as he has started every project late (he did smoke remediation under a different contract) and is not that great about answering questions.