When you open gimp or paint just save it as "guardar como" in spanish, then you click it, you are going to see 2 options "Nombre" and "Tipo" you click "tipo" you are going to see some options like this:
-PNG
-BMP
-GIF
-JPEG
-TIFF
-TGA
-Directdraw surface
You have to click TGA you save it, but when you save it you have to go to "Mi equipo", after "Disco Local C", then "Games, when you are in-games section you are going to have 2 options (I think):
Toribash-3,91
Toribash-3,94
You would have this option if you have the new and the old version. Just click the 3,94 option your pc is using each file from the new version.
After you click this option you are going to have more options:
-Autosave
-Custom
-Data
-Raytrace
-Replay
-Screenshot
Click Custom option.
In the custom folder you will find each texture from each player that you have ever saw, you have to look for your name in this case "ShadowGS" or just made a new folder with a name like "prueba" or whatever you wish. When you already click your name (The folder that contains each thing that you have or you have made) or the name that you made you have to choise the file "TGA" then save.
After all this shit you have to go in-game and write: /lp 0 "here the name" ( yours or the one that you created)
You will see the texture that you want to look.