On the lower unit there is a slot screw and a star shape DON"T take the star out. The flat screw next to it can come out and the other flat up higher can come out to change the oil, check gas lines and maybe the bowl on the carb, looks like good, when you get in running check to see the temp. of the water coming out if its warm -hot you may need a new impeller if fact I would change it to be on the safe side, four screws to drop the lower unit and one screw for the linkage for gears.