the Pressure Temp safety valve is leaking on the water heater so i get to go to the hardware store and buy a new one and install it. that means i get to use the sawsall! anyone replaced this. i have been told to leave the tank filled as the extra water will help keep the tank from getting tippy when i put the wrench on the valve. also they said the valve can get stuck and you need a big wrench and a cheater bar.