Tenants won't know where or when you'd use that old lockset again, so it's as secure as one off the shelf (assuming you aren't rotating locks on the same multifamily) as long as it's not on their old unit after the next tenant is in. 3) If a locksmith can rekey your locks as is, that will be a one time cost you don't recoup.

They even go as far as bringing a locksmith, breaking in and changing the lock so they can show the house to the potential tenants who become the victims of the scam and they run away with all the cash. 

If the landlord took money to provide below-market housing to the elderly and disabled and now wants to force them out, he is a giant welfare queen and should be resisted.On the other hand, be prepared for the possibility that the low rent and bad maintenance were the result of bad property management by the guy who died, and the new company is just taking care of things (inspections, maintenance, re-keying, leases, rent increases) that should have been happening gradually over the course of years.

Ideally, a locksmith would just come out and change the chambers but I’m not sure if that’s a thing.

We will show up on December 9th with a locksmith to let us in our new house. 

Use Rekeyable locks.Use MyKeyHero app.

Perhaps even a master locksmith could do it.

I gave her 2 options I can call a locksmith to help, but she will be billed or I can make my way up there which would take about 1 1/2 hours.

You also bring along a locksmith to change the locks.

This keep most lock smiths from making copies.