I am trying to remove the lift cover on my 1950 8N. I managed to remove the rocker pin and the left lift arm pin, but the pin that holds the knuckle above the leveling box is frozen solid. The end of the cotter pin end looks mushroomed some but that is no preventing it from moving. I have soaked it in PB blaster, heated it with a propane torch, frozen it with a can of dust off upside down, but it doesn't budge with a drive pin and a 4 pound hammer. It is frozen in the knuckle. I have thought about cutting the cap end off and trying to pound it out that way, but the metal is pretty hard. I'm sure one of you have had this happen. I am worried about breaking the knuckle casting. What am I doing wrong?