I have an opportunity with a seller who is willing to do a lease to own contract for me to purchase a home he bought and is now ready to flip.

We could buy all of the land and lease them back the building for $1/year or something, they are really flexible. 

My lease doesn't specify when a late fee is to be collected but it does specify that if rent is not received after the 10th day of the month a late fee is assessed.

The lease says to pay by the 9th and today is the 16th.

This would be my first commercial property and while it has some tenants already I know these can be a bit more difficult to lease out than a 2 bed 1 bath. 

First you schedule a walk thru of apartment so you know if you want to renew them or not,, crappy house keeping,, what ever is almost good enough reason for me not to renew.Download a lease renewal form,, give within proper notice period,Raise rent if it warrants a raise, you need to market check your area.. 

If someone is looking to make a BIG move, there is the opportunity to do some pretty significant value add and increase rents, but it would take a year or more to get it all done with current leases in place.  

I had a previously excellent tenant break their lease. 

I highly recommend reading How to be a Landlord written by a Newton, MA lawyer:http://www.attorneyross.com/landlord.pdfI use Lease Runner to create my Massachusetts leases & accompanying documents which are then signed online by me and my tenant.

The lease that I am using is as up date date as any lease for the State of Minnesota, and it includes "Lead paint warning and disclosure.