First spray all of the studs and cones with a good penetrating oil. Then strike all around the inner steel part of the drive tire (not the hub) with a sledge hammer HARD to loosen up the cones. You also may have to use at least a 2" diameter rod at least 4' long and smack the other side of the tire HARD from the opposite side of the truck. Try to hit on the steel part of the tire and not on the rubber.