What is the problem?
I've recently moved, and my wifi information is out of date. I need to update the supplicant file.
What did you already try to solve it?
When I plug the SD card into my computer, I can't access it. The PC says the disk must be formatted.
When I connect the Pi through ethernet, I can get to the desktop by VNC, but I don't see any way to edit the file.
There's a config page showing many useful features (like text editor) disabled.
So I'm in a catch-22, I can't edit the file through the wired connection, and I can't edit it by mounting the card on my PC, and I can't enable anything that would let me edit the file.