When ever I put water in my radiator it runs out of the water pump on time so I wanted to know the steps for changing one and also if it needs changing or can it be fixed without changing it.

The water pump is run by the timing belt. In order to replace it you'll need to remove the timing belt (you should replace it also). I would get a manual as it is too detailed of a procedure to explain it on here efficiently.
If it is an Si then it is the dual cam engine and is more complicated. Non-Si is a single cam engine and it isn't too bad.