To change a water pump, you would first need to remove the serpentine belt. You then disconnect the coolant hoses from the pump. There should be bolts holding the pump in place that need to be removed and then the pump is out. To install the new one, reverse the order and fill the coolant back up to the correct level (you will loose coolant and most likely have a small mess when you disconnect the coolant hoses). Depending on the design of your engine, this could be a very easy job, or moderately difficult. Never perform this job on a hot engine and be careful around the serpentine belt. If you need help, ask for it. It is better to be safe and make sure the job is done right. Good luck.
〉 Answered on Nov 26th, 2007 by Suzanne Grego, Technician at City of Philadelphia Fleet Management