Copy the following text and paste it into a text file, then save that file as "chrome.manifest":
skin global My_Theme jar:chrome/My_Theme.jar!/global/ skin mozapps My_Theme jar:chrome/My_Theme.jar!/mozapps/ skin messenger My_Theme jar:chrome/My_Theme.jar!/messenger/ skin messenger-newsblog My_Theme jar:chrome/My_Theme.jar!/messenger-newsblog/ skin communicator My_Theme jar:chrome/My_Theme.jar!/communicator/ skin help My_Theme jar:chrome/My_Theme.jar!/help/ skin navigator My_Theme jar:chrome/My_Theme.jar!/navigator/ skin editor My_Theme jar:chrome/My_Theme.jar!/editor/