Tenant's Not Responsive and Lease Ending 1/31/16

[John Hockaday]

I own a rental property in Lakewood. Two tenants currently reside there and have been there for almost a year. Their current lease expires on 1/31/2016 and I notified them via text and email to let them know that they need to give a 30 day written notice if they intend to move out. They have not responded to me and are apparently ignoring me. What is my next legal step of action. I want to make sure that I do this all the correct way.