Tenants moved out

[Mike Kooser Sr]

I had tenants on a month to month lease yesterday I caught them moving out without notice. They said they would be gone today .  I went by and there are things still there with front the unlocked. Noone is there and the won't answer calls or texts to verify they are done moving.  How should I go about changing the locks and getting the house ready to rerent? 

Can I just do it or is there a legal procedure?