Which margins are you talking about? The ones in the Paper Size definition for the printer are what matter. Are you trying to print at 100% a page that is the same size as the paper? Or are you trying to get your page to print within th printer's margins.
If the former, then you need to buy a printer that prints to the edge of the page. If the latter, then use the custom page size feature of the print dialog to create a custom page for your printer with a 1/4" bottom margin.