If I am unable to get to the property, the tenant will be charged for a locksmith, but under no circumstances are they to remove screens or try to break into windows.  

Re-keying locks is pretty standard.

**Relevant information:- Third floor cannot be a permitted separate unit--there is only one entrance/exit stairway (MPLS requires two), and no sprinkler system (which would allow us just one exit)- Third floor electric and gas can be measured separately, but all are under the same bill- By rekeying two doors, there could be completely separate access to the second and third floors- Current second-floor rent is $2000Option 1: End Lease and Rent as a Full UnitThis is the most straightforward option. 

Are they putting in new hardware, or rekeying??

Address the unauthorized lock change, request the return of the original key or permission to rekey locks.

Starting out it would be tough to be hired directly with asset management company.Typically we are only authorized a set amount for re-keying, mowing etc.For example the last one we did we could pay $100.00 for rekeying house and $30 to mow the grass every 2 weeks.

Then I would show up with a locksmith and change the locks.

It's fairly quick to change these out on the units.On some places I started switching over to SmartKey locks. http://www.kwikset.com/smartsecurity/re-key-techno...They are convenient.

Also have a locksmith present when the cash for keys occurs.

We use Kwikset Smartkey locks which can be re-keyed very quickly/easily.