In any non-online section(like instant action)choose the game type,choose the game map,wait for the game to load,and when the game starts,press fire for the game to start,and then,press ~ to bring up the console and type in god of time.Press enter to activate the code.The effect stops time but makes you able to use your weapons(it makes time stop but makes you able to fire both regularly and alternately with all of current weapons that you have(the code makes time stop,but makes you able to fire both regular and alternate ways with all the weapons you currently have).