The correct place to lift the engine is the oil pan. Place a wide piece of wood such as a 2x6 between the floor jack and oil pan to distribute the weight from the engine over the entire bottom of the pan. Then as you are jacking it up be sure to carefully monitor that nothing on the engine is preventing it from moving up, such as the fan hitting the shroud. You should then be able to just take out the old mounts and put the new ones in.