Undo symbol library upgrade to 5?

I’ve been using Kicad 5 with the symbols and footprints from Kicad 4 for quite a while. Today I decided to upgrade those to 5 as well, by deleting my fp-lib-table file and picking the default setup (see I had KiCad 4 installed previosly. Now i updated to v5. Now i have some problems with the library setup).

While that worked, I realized that upgrading my project still meant recreating the layout (not literally, but the amount of work might be the same).

So I restored my old fp-lib-table, and while Kicad now shows the old footprints in the Assign Footprints window, the symbols still belong to Kicad 5.

What additional steps do I need to perform to get Kicad 4 symbols back?

Well the tutorial you link gives you both options in detail. Might want to reread it.

I decided to purge and reinstall Kicad 5 and to restore my ~/.config/kicad from backup instead. This gave me back my Kicad 4 footprints, but not the libraries. In which file are the symbols libraries defined?

I couldn’t follow the tutorial since I DON’T KNOW where my Kicad 4 symbols are on my disk – after upgrading my Kicad 4 packages from to 5, the Kicad 4 packages are no longer installed, but I was using Kicad 5 with Kicad 4 symbols and footprints.

I finally installed Kicad 4 libraries. Of course, the “official” ones aren’t the ones I created the project with, so I’m not sure if this is of any use at all.

I guess that means I throw everything away and start over in Kicad 5. Great job!

No need to throw everything away. Just make sure you have the cache lib and you can use a project with old symbols even if you no longer have them on the system. They will just be rescued.