Im trying to remove the pully from the transmission on a craftsman riding mower. Does anyone know if the pully or shaft has to be heated to remove? I've soaked it with wd40 and it still won't budge!

After you remove the retainer ring the pulley is held to the shaft with a key woodruff. You should be able to lift it straight up. Be careful if your try an tap it or use a pulley puller. That pulley is welded stamped steel and could bend if too much force is applied.