20 hp 4 stroke gear question

[gt1624]

Hey ya'll, so im replacing the the gears in the lower unit this weekend and i was wondering how do you remove the pinion gear from the shaft? I see a nut on the bottom of it but there isnt much room to get a wrench on that nut? Is that how it is removed?

any other tips or suggestions for when i do this?

thanks for the help!