To answer your question, visit county Sheriff's office or court and you will figure out.
I went through this twice.
The first time I went all way to eviction court. The second time I just talked to the tenants and ask them to leave. The evicted tenants trashed my place. The second tenants left my place in good order. From my experience, it is much easier for both parties to work out a deal.
Every state/county has different laws, but you can always start from county court and Sheriff's office. I just went to the Sheriff's office they hand me the detail instructions.
Basically, you need to serve the tenants 3 notices(in my county). Tell them you will file eviction if they do not pay. You have to serve the notices exactly the way court tells you. Once the notices have been served, you go to court and file eviction. Court will schedule a date and you just tell judge that tenants have not paid since xxx on court.
Hope this help.