1. Put it directly onto the head, splitting it so that the left half of the name shows up on the right side and the right half of the name on the left side.
aka if your name is "VOLT" you would put VO on the right side and LT on the left side.
2. To test your head in single player, go to your Toribash folder, then to the Custom folder, and find your name OR if you can't find your name, make a folder with the same name that you use in game (excluding clan tags). Put your head (TGA format, should be 49kb) in this folder as "head.tga" then load up Toribash and good luck.