I have been separated from my spouse for two and a half years how can I get a divorce threw the newspaper

You file for divorce in your jurisdiction and then you go through the process of divorce. You have to attempt to find the other party and if you can't then you can ask a judge for service by publication.

You can't get a divorce through a newspaper, only a court can grant a divorce. You can use a newspaper ad to serve notice of the divorce if you have been unable to serve him any other way. But first you have to submit a petition for divorce to your local court and attempt to serve him.