Update:The attorney got back to me and stated that if the other party does not reach out to me directly, don't bother reaching out.He also said that the other party's simplest recourse could be arguing "unjust enrichment", but the very material counter argument would be that they have, while trespassing, installed a non-permitted and non-warrantied roof. 

I am not sure what paperwork is needed for this but it would likely be the simplest option here.

What is the simplest way to handle this ?

The simplest way to do this is find an off market deal.

The loan terms simple state that you have to make your payments.

I thought I would have this issue with kitchen cabinets but that was the simplest of all decisions.

Let's assume you have $2K to put towards the down and want to use private money for the rest.The simplest approach is to give your private lender a second mortgage for their payment ($8K).

It seems like the simplest way to do this is to cut a small section out of the concrete to run the wiring.  

Assignment is generally simplest and best.

But for the most part, I think that's the simplest way to put it!