I didn't make it!
Use new textures? Do you put it into a shader? If thats the case how the hell are you supposed to do it?
To use your own custome textures do this:
1. Make a folder in your "base" folder called "textures" 2. Make a folder in your "textures" folder called "whateveryouwant" 3. Put all your custom textures in that folder 4. In radiant, go to the texture menu where you that looong list of names (eg. bespin, bespin_shaders, etc.) and look for your folder name. eg, I called my folder "whateveryouwant" so I'll look for "whateveryouwant" in that list.
And that's how you do it :D Note: Each time you add textures in that folder you have to restart Radiant so that it will recognize those textures.