How to replace the water pump

My van started overheating and the battery went dead which is probably 2 seperate issues but need to fix the overheating first. It overheated, I checked cooling levels, seen small drip. Checked hoses, no leak. Radiator is new, thermostat is new. (New is 4 months old) when we finally were able to determine leak it appeared to be coming out of engine. At bottom where I would guess the water pump is. Does this sound like water pump and can I find out without having to pay a mechanic because Im broke. Also if you could give me a good idea on how to chane the water pump on this engine becasue it is foreign to me. Any help please. Thank you