Help to remove nut on 40hp driveshaft

[DavidMc]

Yes, I hit rocks...twisted the drive shaft off at connecting at the top. How do you remove the nut in the lower unit to pull old driveshaft and put in new....what size wrench, left or right handed threads... special tool? I tried 18mm and 11\16...both seemed too big...17mm won't fit. any help from you techs would be appreciated.

Thanks, David

40hp, 4 stroke, 3 cylinder, not big foot, 2001