Easy. Go to the auto parts store and say you want a rear dual exit pipe for a 96 Taurus w/Duratec engine. They will give you the pipe and all you have to do is get some mufflers and tips for it. I recommend getting it installed by a muffler shop. Alternatively, a muffler shop can cut your pipe and run a second pipe over to the other side for another muffler. The pipe itself shouldn't be more than about 40 bucks.
edit - Oh and I see its your first post. Welcome to the TCCA!
I got the dual exhaust from a '98 model. It was chopped off about 2 feet in front of the rear split, so basically it was just the two mufflers and the Y split. Then I chopped if the OE mufflers, welded on some MagnaFlow's, chopped off the existing single muffler, and welded the duals onto the old pipe. Very simple and cheap.