Put in the new smart locks to save re-keying cost next time.

Kwikset sells a Smart Key system that lets you easily rekey the locks in seconds.

I am writing out all the damages to the property and my contractor is going to give me a receipt... the damages will contain the locksmith cost for changing the locks because they did not give me the keys and they broke a key in the back door lock... the waste removal, the repainting of one room that was painted black and one wall in the dinning room I have to paint because they painted it orange...

With my last rental we found a lockset that can be rekeyed really easily without taking the lock off. 

Having a matched set of locks with one master key that takes 10 seconds to rekey is freaking amazing.

If so, just ask for the key and then rekey everything and take that out of their security deposit.  

You will be facing expenses to rekey the building so you have a master key.  

Make sure not to pay him until all his stuff is out and you have keys so you can re-key the place right there and then with a paper signed saying he relinquishes his interest in the property for X amount.

Hi, I am thinking of installing these electronic keyless locks to avoid rekeying fees for new tenants.

With homes that have been tenanted 3+ years, it is likely that you will need some updates along with the general cleaning, rekeying, and minor repairs.