In this instance, how would a lawyer be able to defend his client?

The client went to court and the judge made him come back 2 weeks later and suggested that he got a lawyer and he did. Let's say a lawyer was hired after his client already gave a statement admitting everything to the police, and the evidence against the accused was very compelling. How can the lawyer in this instance help the accused? The prosecutor has already signed an Initial Sentencing Report. Can the lawyer persuade the judge to minimize the sentence? What else can he do?