you need to have the pressure off all of the rockers on that shaft, you can slide them off to the side so that they are not on the cam lobe, if theres not enough room to go one side you can pop the clip and slide the opposit side rocker out of the way and slide the rocker to the other cam lobe, if it's just dirty and you can't get the shaft to move, clean it and soak it down with wd40 or pb and keep at it, once you get enough sticking out grab it with a big pair of vice grips and twist as you pull