Upgrading game project to 4.1, without "properly installing" the update

The 4.1 update notes say:

But I do not have that option on my right-click menu, probably because it would be registered when you install 4.1 from the Launcher. I am downloading and building straight from the source, without installing UE4 via the launcher.

So, how do I update my game project to 4.1?

Hey Jefferson! Sorry about this, we’re still improving this process and trying to more closely unify the GitHub and Installed workflows.

Locate the file /Engine/Binaries/Win64/UnrealVersionSelector-Win64-Shipping.exe and run it. This should install the shell commands that you’ll need to upgrade your code project and generate fresh project files. This is indicated in the latest GitHub README for 4.1 as well.