Start by cutting back the fat layer on the top of the brisket to expose the meat. Then working from the thin, square end of the brisket, cut long thin slices about the thickness of a pencil. If you find that the brisket is a little tough, cut it thinner. If the brisket starts to fall apart cut the slices thicker. As you work your way along, trim off any large pieces of fat.
Once you get to the point end of the brisket you will find a second layer of meat on the top. You should now be able to see the strip of fat that divides these two parts. Cut through this fat removing the point from the flat. The grain of the point runs differently from the flat so it needs to be cut in the other direction.
With practice you shouldn't have any trouble carving a brisket and, after all, the meat is so good few people will mind if it isn't cut to win a competition.