Thak you very much, dpoulton, for the greeting and the answer.

1 - You're saying that I should copy (and save elsewhere) the current joplin-desktop folder, and then replace with it the new folder that will be created after a new installation.

2 - How do I do the replacement? Command "paste in", and then to be asked "there's already a folder with that name, do you want to replace it?", and "yes"?

3 - There's also a folder named "Joplin" there. Don't need that one, right?

4 - Also, if you don't mind, is this method fool-proof? Anything I should be extra mindful about?