Prop changes are quite simple and require very basic tools and understanding. Have you a manual for this engine? This is the first "tool" you purchase for an engine of any type. You'll need a wrench, screw driver, maybe a pair of pliers and a small, light weight deadblow mallet. Just looking at it, you should see a cotter pin or nut with a sheet metal washer, folded up around the nut flats. This should make removal apparent, if not - do yourself a big favor and look up "outboard prop removal" on YouTube, as dozens of videos will show you in 5 minutes or less. Simply put, if removing the prop requires asking, you really need a manual bad.