Just wanted to add to this post since I have done this repair twice (don't ask). Anyway, I strongly suggest take the extra step tp remove the radiator, its only 4 additional screws and 2 more hoses to remove. By taking out the radiator it made it MUCH easier to access and get leverage on the top water pump bolt, and I was able to manipulate the hoses onto the thermostat much easier. Also, if you remove the radiator, you don't have to take off the passenger front tire and cover for the wheelwell which was a HUGE PIA the first time I did it!! This also lessens the chance you will puncture the radiator which trust me is NOT CHEAP!!