You can then go ahead and do with the money as you please, for example build a new house.It's fine to tell them you don't know how this works and ask them to explain.

Fees should be justifiable and easy to explain.

You could tell them they can have the last month free and they might appreciate it so much that they'll choose to leave the place spotless (good luck with that).Personally, I would write them a very simple letter explaining that there is no deposit, they still owe rent for the last month, and their responsibilities for leaving it clean.

Do you have contact with a representative of the employer who you can contact to explain to them the situation?

I recommend speaking to a local lender to explain your situation.Where are you located?

Thank you for explaining some of those things.

@Dante FortsonFirst off, you didnt explain ANYTHING with your first post.

It is best that you explain your goals so they can better assist you.

The object of the game is to reduce/eliminate your cost as low as possible while maintaining positive CF, and let your tenant pay for the rest from the rent. 

@Caroline Gerardo care to actually explain why?