Going nuts - Yamaha engine HELP!

[Birchbark]

I thought it would be simple to replace my water pump impeller on my 2006 150 Hp Yamaha 4 stroke! I removed the six bolts on lower unit, tried to remove the bolt holding the zinc o , which is inside the shaft about 10 inches down a very dark shaft. Question? What size nut, bolt head is on the fastener? Other problem is one of my sockets is stuck at bottom of shaft. And I thought it was going to be easy! HELP PLEASE

Birchbark

 

[Kelowna]

Birchbark, sorry to hear the repair is not going smoothly. While I don't know the answers to help you, even if I had a year. It might be a good idea to post what year your engine is for others to help, as the answer may change by year.
I hope you get it fixed soon.