What is the appropriate course of action in this case?

As a result of the trial court's imposition of an unauthorized sentence, the appropriate course of action is to remand this case to the trial court for resentencing. (People v. Massengale (1970) 10 Cal.App.3d 689, 693, 89 Cal.Rptr. 237.) Upon resentencing, the trial court retains discretion pursuant [230 Cal.App.3d 193] to section 1170.1, subdivision (h), either to impose the one-year enhancement provided by of section 667.5, subdivision (b), or to strike it as long as the trial court finds mitigating circumstances and states its reasons for striking.