Steps to take when tenant vacates property early term?

[Craigx Dies]

Hello All,

My tenant notified me that they needed to early term their lease agreement.  They have paid through the end of the month however have moved all of their belongings out of the house.  According to the lease they signed they are responsible for their monthly payment until lease term or until I sign a new lease.  Few questions...What steps should I take?  Can I change the locks?  What are my pitfalls?  What is the best way to communicate/ remind my tenants that they are legally responsible for their monthly payment until I get new tenants.

Any advise is greatly appreciated. 

Thanks,

Craig