You can rewrite about as much you want.  The biggest restriction on that is trying to keep existing links intact, which means either avoiding renaming or removing sections, or being sure to keep a reference to the old name.

I have reservations about suggesting the "Python (command line)" Start menu entry over just using Command Prompt (since it's really just Python running inside a Command Prompt-like window with even fewer features that will disappear as soon as Python exits, which may make debugging a challenge in some cases), but I'd like to see what you have in mind before judging.

To generalize an idea that I touched on in my last message, I don't think the Python documentation should be trying to teach people how to use Windows.  We should provide links to good resources for learning particular topics that are necessary for what we need to teach on the Python side of things (such as how to set environment variables), but we shouldn't try to keep it in-line.