When it comes to winterize, the manuals are not always as good as we might like but there is a lot of info online and it can help.
Are you a person who likes to see drawings and do some looking? If so, there is a great tool:
And plumbing specific here:
It takes a bit to learn to"drive" the first but it is interactive and you can turn things around and over to get a really good look at where things like drains and valves are located!
BAH! The system seems down at the moment, so I can't give you an example of what you can find . Check on it later, perhaps and shoot any questions if not obvious how to work through it! The info is there but not how to find it at times!!
Good luck with the the phase of life. It seems like we just have to keep adapting the what we find!
When the manual tells you to open a valve but not WHERE???