I gave the firmware link!
https://pgaskin.net/KoboStuff/kobofirmware.html
It even explains install, except I would extract to your own disk and then copy the files. It's the same thing.
Make sure you register with real or fake email via WiFi after the reset. DO NOT EDIT THE DATABASE!
Let it update. Disable WiFi
Connect to USB.
Make sure you can see the .kobo directory/folder (On Mac & Linux enable view hidden files)
Download desired FW version (either 4.32.x or current 4.34.x)
Unzip to a folder/directory on your computer.
Copy all inside that into inside of .kobo
When it's done, do the usual OS Eject.
After a little while the new firmware will install.
Then edit the confg for SideloadedMode=true.
Don't edit the database!