Right. I might be able to help you with this.
#declare headdir="C:/Program Files/Toribash-3.3/raytrace/";
That needs to point to where your Toribash folder is. ie:
#declare headdir="C:/Games/Toribash-3.6/raytrace/";
Put the .tga files you want to use as head textures in Toribash/Raytrace.
Now you need to specify what the files are called:
// Use a head skin and name of skin (takes from the heads folder).
// Player A.
#declare playerAskin=1;
#declare playerAname="head.tga";
// Player B.
#declare playerBskin=1;
#declare playerBname="head.tga";
Example: if Player 1's head was called tori.tga and Player 2's was called uke.tga, you'd need to change the script to the following:
// Use a head skin and name of skin (takes from the heads folder).
// Player A.
#declare playerAskin=1;
#declare playerAname="tori.tga";
// Player B.
#declare playerBskin=1;
#declare playerBname="uke.tga";
etc.
Tell me if you have any luck.