I think that on that engine, you remove the cowling and look at the motor, finding the shift linkage. The rod slides on to that and is held in place with a cotter pin. Remove the cotter pin then the rod slides out with the lower unit.
On other engines, I have seen about half way up on the front side of the motor, there is an opening and they have two nuts, loosen them and it separates. On my engine it has a compression pin instead of the nuts.