Walk me through a short sale?

[Terry Royce]

I understand the overall concept, but can some of you that have more experience give me some advice / guidance on what to do during this process.

I have my authorization from the owners.
I faxed it over.
The property has been sitting vacant, filled with mold and needs gutted. Loan balance is around 15k ARV 110k Repairs 50k

How do I negotiate with the bank?
What should i NOT do?

Thanks