Its kind of a pain depending on what pump it is. I replaced both of mine last year. To get at them you need to pull the whihe plate that is under your oil tank. then you will have access. If it is your recirc pump you will need to unscres the old pump form the valve and screw the new one on. the thru the hull one you will have to seal the thru hull fitting. in both cases you need pumps with the 90deg bend on the input. i highly reccomend mayfair cartridge pumps, the cartridge is very easy to change compared to changing the whole housing.