How to upgrade to version 4.18?

I’m trying to upgrade to version 4.18, how to proceed?

You can add a new engine version in the library, it’s accessible from the launcher. Once you have it installed, launch the editor and open your project - you’ll be prompted to update.

If your project is 4.17 and you only have 4.18 installed (4.17 has been removed), you will get an update option when launching your project as well.