Re: 6 hp lower unit removel
3 bolts to remove. Two from underneath and one at the front from above.
No joint in the shift rod, it simply pulls from the mechanism ( a couple of bevel gears) at the top.
The drive shaft pulls from the crankshaft.
The water tube pulls out from the water pump
I agree change the pump impeller while its off. The driveshaft oilseals too perhaps
While it is off connect a hose to the water tube to make sure you can get a good flow through the engine.
The grommet at the top of the water tube can be troublesome. Corrosion around it squeezes it over the top of the tube and blocks the water flow. It is a power head off job to sort it out. A real PITA
BUT what do you mean by the "lower unit gasket" and why do you think there is gasket that needs changing ?