need help tearing down powerhead

[awthacker]

Because my motor seized up, I'm trying to disassemble it to find out where the corrosion was and how it got in. I have pulled my cylinder heads and the carbs and am now trying to pull the front section of the block off of the powerhead. Is there any secret to it? There is a shifting rod blocking me a bit. It's circled and pointed to in the pictures. Am I gonna have to drop the lower unit? I'm trying to leave as much intact as possible because it is already going to be a huge challenge for me to get this thing back together (if it ever happens).