[Endoperez]

If you mean the borders on the (random or other) maps, you need just a graphics editor that can handle .rgb files. Then go to the \maps\ subfolder in Dominions main folder, choose the map you want to edit, and edit. As long as you don't add or remove any of the pure white pixels (255, 255, 255) that mark the center of a province, you have nothing to worry. You might copy the map somewhere safe, or move the white pixels to another layer on your graphics program of choice, or do some other preventive measure to make sure you don't accidentally add or remove any provinces. That'd mean you have to edit the .map file, which has everything from terrain details to neighbouring provinces.