Currently, only some info has been discovered. No editors yet exist developed for the game.

Note: most things provided here are a copy of TTYD: Texture Hacking

Let's start.

Our goal is going to be to change the PURPLE mouse to a LIGHT GREEN mouse and maybe add some more features to him.

Open Dolphin Emulator and click on the Graphics Icon on the Main Menu Bar.

Next, you need to go to the Advanced section.

Now, check the box that in labeled Dump Textures.

Next, you need to find your way to this file: (dolphinemulatorpath)/dump/textures/G8ME01.

You can minimize this folder for now, we will need it in a second.

Now, leave and reenter the area with the Purple mouse to make sure that the image is loaded by the emulator.

Now, open the folder and find the image that has the Purple mouse in it.

Copy the image and place it on your desktop (do not change the name of the image).

Next, we are going to edit the image. Open the Purple mouse image in your image editor.

Edit the Image to your liking (in this example have the main colour green).

Save the image with the same name it started with.

Now, go back to the Graphics settings on the emulator and uncheck Dump Textures and check Load Custom Textures.

Finally, go to this file location and put your custom sprite/texture in the folder.

If the image doesn't load at first just go into the graphic settings and uncheck and recheck the Load Custom Texture box.

Enjoy playing around with this! Purple Mouse to Light Green Mouse.

Final result:

Thanks for following this tutorial, initially created by Drewworks. Again, I woud reccomend checking the thread with link at the top of the page.