Use the Select and Zoom tool to zoom in on the particular area of the PDF page that you want to enlarge for printing. Once that is done, hit CTRL+P to pull up the print dialogue. Click the radio button for "Current View," and then select Fit to Printable Area under the Page Scaling drop-down menu.
Hope that helps!
Jason Covey
PDF Litigation Solutions, LLC
www.pdflitigationguide.com