How do I manually print on both sides of the paper?

Select Print from your software program, open the print driver Properties/Preferences, click the Layout tab, select the appropriate duplex option from the 'Print on Both Sides Manually' drop-down list, and click OK. After the first side prints, retrieve the stack and place it face-down in the input tray with the top edge first, then click OK at the computer to print the second side.