A method for operating a printing press for carrying out a forme change and a format change on a sleeve-based printing unit of the printing press, in which a rewritable or erasable printing sleeve is used as printing forme includes setting images on a printing sleeve outside the printing unit of the printing press, wherein the printing sleeve which has images set on it outside the printing unit is positioned on a forme cylinder of the printing unit together with a spacer sleeve which is adapted to the format to be printed, for carrying out the forme change and format change.