While cold and engine off lol. You have to lift the radiator up with it full and it's cap closed and tank cap open till coolant comes out the top of the tank and coolant flow down to drivers side coolant tube. If coolant does not come out of tank add more into the tank and repeat till it comes out. It worked for me the first time. If you still can't get it pm me and I will send a more detailed list of what to do.