replacing water pump.

That depends on you. Have you ever replaced a water pump before? Do you have a Chilton's manual or another repair manual to give you step by step instructions? If the answer is "No" then take it in and have a professional do it.

The water pump on your engine is driven by the timing belt, and is not something I would recommend doing without a hoist.

it'll save you a lot of money doing it yourself but its def not easy, if you dont have much experience with these things, have a shop do it.