My paperback bleed issue while publishing

This is the issue I have: Add 0.125" (3 mm) to your book's page width and 0.25" (6 mm) to the page height to ensure that the images in your manuscript extend beyond the edge of the page. This prevents white edges when the book is trimmed. See examples PDF page(s) xx-xx-xx. I can Pay 400 INR for this, Anyone can help me.