The Toy Editor allows users to create custom toys that can be used in the game. Modifying the base color and reflection map can be done easily in the editor. The main toy texture can also be replaced, allowing you to create a wide variety of toys and props.
Before thinking about modding the toy's texture, download the toy's default texture, square toy's default texture.
As long as you didn't use the Stealth Mode during installation, a new entry in the start menu should be available for you. Just browse through Start > Programs > thriXXX > [game name] and click on Open ToyEdit folder. A new explorer window opens, and this folder, right there, is the one and only location to put new images to use on your custom toys.