Most of the necessary changes are in the .tilespec file. Some new data needs to be added to the tileset. For non-iso tilesets you should copy the data from trident.tilespec (in the main distribution) into your tilespec files. For iso tilesets copy the data from isotrident.tilespec, and for hex tilesets from isophex.tilespec. Of course, results may vary from tileset to tileset.