Complex sentence: For instance, the city of Rochester Hills does not have its own police department, but contracts with Sheriff's Office for an established sheriff substation in the city with deputies dedicated to Rochester and operates as the Oakland County Sheriff's Department, Rochester Hills substation.
Split into simpler sentences: For instance, the city of Rochester Hills does not have a "Rochester Hills Police Department," but instead has an established sheriff substation in the city with deputies who are dedicated to that city only. That branch operates as the Oakland County Sheriff's Department, Rochester Hills substation.