You get the locks changed back and charge him for it, you give hi a 3 day pay or quit notice for nonpayment and then you evict him.
I just got done with this exact situation. You've already given a 30 day notice. You don't have to wait for that to expire to issue a notice for termination due to non-payment. That may get him out sooner since most states only require 7-14 days notice before you can file in court.
Otherwise, you file in court for eviction due to failure to vacate if he's still there after the date specified in the 30 day notice he has to be out. Then a judge will decide when he has to be out. If he stays after that, you can have the police remove him. Then you change the locks and charge him for all that as well as any cleaning and damages.
This is a legal procedure you must do from start to finish. The sheriff comes and watches him move his stuff. Literally watch him, doesn't help at all. Then you need to rekey everything.
You will have to sue him to recover any money. And make sure you contact his credit agencies so his credit is affected for his nonpayment. After all, he did not pay in a timely manner.
There is no "next". You finish the eviction. It ends with the sheriff removal.
We've done that, what next?
You start an eviction action.
