I think its kwikset (but not sure) that make landlord friendly door locks. you can have it set that 1 key can open all the doors and you can easily change out the lock tumblers to rekey it. basically you have a master key, while all your doors have a different key that only opens that specific one.I think they also make solar powered w/ back up battery electric locks that you can use if your leaning in that direction.  

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...

If the lock has been changed without proper notice and you have not given management a duplicate key, a locksmith will be called upon to open the door and rekey the locks.

They are a pretty quality lock and they are really easy to re-key when the need arises.

Lease still had 3 months left @ $500/mo, and there was $3k worth of damages (broken window, 2 damaged doors, holes in walls, broken cabinet doors, marker/ink all over the walls from kids drawings, snuck a pet in against the rules/regulations and feces on carpet, blinds ripped up) plus typical cleaning and turnover fees.....only had $450 in security deposit which I of course held.She left and didn’t bother sticking around to turn in keys so I posted notices, etc. and after several days and 4 attempts to contact, finally removed all the junk, rekeyed, and fixing up and now have a new renter set to move in 3/15.

I have used A1 locksmith most recently.

You will need to clean and make repairs, rekey/change locks etc. 

I'm guessing that technically it would be illegal--constructive eviction--to rekey the locks after he leaves, since he is still on the lease.

I actually just did this recently and bought some cheap ($1000) houses, then had a locksmith open the doors and re-key the locks....I paid him using a debit card from my business checking account (credit cards are not allowed). 

I don't have to wait on any contractor and/or locksmith to rekey it.Just make sure you have a copy of the current key and then you can rekey it to another key yourself.Put in the old key, turn it a quarter turn, then put in the rekey tool into the separate little pin slot until it clicks the lever in there.