Not at all. I have a '77 model 115 Evinrude. You have to remove the black air box extender, shift and throttle cables, the choke solenoid and then you're good to go. On mine there is a two piece pivot arm that has a pin that goes through the shift rod. One large pivot bolt holds this arm to the block and it connects to the arm that moves with the cable. Five bolts hold the lower unit in place and it's out of there.
I replaced the water pump gasket, the gasket that is pressed into the metal plate on top of the H2O pump housing that seals the drive shaft, the rubber seal that goes around the metal plate and seals off the mid section from the drive shaft and the lower unit to mid section exhaust housing in the mid section. Mine looked original and all messed up. Put an o ring on the upper part of the drive shaft just below the splines. Nothing was there when I removed it.