Usually I would have the locksmith meet them during the walk through to change the locks and get new keys.Any repairs I would call the repair person after reading reviews on yelp or google or use someone my friend recommended.

This has also saved my tenants a call to a locksmith or me when they have locked themselves out.  

I know locksmiths cost money and I know that turnover isn't always instant.  

It had gotten to the point where I called a locksmith for to get all units rekeyed. 

Do I get a locksmith out and change all the locks?

The PM began calling making demands for L to move out, she said that L had until today to be out and that a locksmith (yeha, right) would change the locks on Sunday morning and that if her stuff wasn't out she would let her in to get her things on Sunday.

Our legal "notice to enter" states we can have a locksmith assist us if necessary and charge the tenant for the locksmith service.

They'll just have to call a locksmith to jimmy the lock.

Eventually I evicted them, but it cost me a lot in legal fees, sheriff's fees, locksmith, etc.

If you don't want to go that route, look for a local locksmith that will do them for you and give you a master key.