Re: omc 600 stringer
The process is to disconnect the shift cable behind the engine inside the shift converter box and then remove the entire drive. Once on the bench, the exhaust housing cover comes off and the upper lifts up and out like delivering a baby c-section.
Use a factory manual. Take the battery out of the boat before dealing with the shift cables.
There is a spring clip on the outside of the intermediate people sometimes miss in removing the cable.
That's a $700+ shift cable so as southkogs says, be careful.
You can (apparently) change the impeller upside down in there the way you are going, but if doing that, people say to leave the shift cable attached and carefully twist the lower out of the way. I have never entertained that method myself, just read posts here about it. Do not disconnect the shift cable from the lower on the boat, you'll never reattach it like that.