1992 Water Pump replacement

Can anyone tell me how difficult it is to change the water pump on a 92 Explorer 4X4? I'm losing coolant and can't tell where it's coming from. There doesn't appear to be much circulation or at least intermittent circulation. Temp gauge only registers intermittently, too and it doesn't overheat. If it's not a total nightmare, I want to just change the pump and all the hoses. Any suggestions?