I have an e-book (for A4 size-portrait) with border and margin of about 2 cm. Since the fonts are a bit big, I want to print two pages on same side of A4 paper (in landscape) and zoom a bit by decreasing the margin. 2 cm of margin on a side while printing a page on one side means 4 cm of margin on the middle and 2 cm on the each left and right side when two pages are printed in same side before scaling (though after scaling there is no four cm margin in the middle but you can see the ratio is same) and that would awful waste of space in the middle. Can I also decrease margin only on left and leave as it is on right so I can bind it?
Open your PDF in Adobe Acrobat, select Tools -> Pages -> Crop Then draw a rectangle around the content you want to keep Then double-click that rectangle
Use this dialog to trim the white margins of your pages, then retrying printing.