It's not as simple as explaining a few steps. I assume you have any of the recent Harlequin versions 8, 9 or 10 and you possibly have the ColorPro activated. You can create tone curves to apply in your PageSetups or do a complete press calibration. You have to follow the Harlequin user guide for all these. The documentation is quite well written and easy to follow. You have the user guide on your hard disk.