EZ...
This is for a Volvo Diesel, but most engines are similar...1. shut off water intake2. unscrew the 4-6 screws on the outside of the water pump. (look for a round flat area)3. pull old impeller, with pliers or use two screw drivers to pop out the impeller. (be careful not to dent or scratch the pump housing). remove paper gasket.(use plastic scraper if needed)4. lube the new impeller (teflon grease works good, as does olive oil)5. insert new impeller. the fins will align themselves. (keep old one for emergencies, if all fins are present and in good shape)6. install new gasket, and pump cover. tighten the screws evenly, crossing back and forth (as you would with lug nuts on your car)7. RE-OPEN the water intake!!!! (check for leaks)8. start engine and check overboard discharge and leeaks at the pump.9. GO SAiling!!Good luck,marc