What are the steps I should take to remediate?

I personally think the remedy is E and O insurance and sellers disclosures.. just because its wholesaled does not alleviate the brokerage or seller from providing Sellers disclosures we all see them if we are doing for real real estate deals with licensed agents. 

We used the insurance company's preferred vendor for the smoke remediation… but we ‘made out like bandits’ on the painting / fixture replacement because they were wrote up  like $8,000 for the work and it probably took us 20 hours of work and $750 in materials to put things back together.  

Building finally resolved and remediated it this year and now i am selling the property.

Is there a remedy that we can remove equipment.

One way to remedy this is to read, listen, read, listen, read and watch everything you can for free about Real Estate. 

Rather than try to force that on him, I would like to know what a reasonable remedy would be for breaking the lease.

Many foundation repair companies (and some pest control) offer services for crawlspaces, to include mold remediation, encapsulation, etc.

As part of the renovation, all of these were remedied however the violations were not cleared as I suspect the renos were done without the full permitting.The purchase agreement had a requirement to clear the violations prior to sale but the Seller and I agreed a fairly substantial seller credit to clear the violations as it was recognized there were risks around the renovation work and potential non compliance with permits that I may have to remedy.

I use a remediation company and he typically sets up 4 to 6 machines.