Edit: I got flashtool to work on pc. It seems the device and everything, but the program does not see downloaded firmwares, even if they were downloaded from the software itself.
What I'm trying to do is Downgrade my Xperia from Lollipop to Kitkat. I have looked this up, and this requires me to use a tool called Flashtool and I don't know how to install the drivers for it, and I don't trust it because I think installing the drivers for my pc and I don't know how to install it in linux.
Because I basically can't install the drivers (im pretty sure I can't turn off driver authentication on my pc) and can't figure out how to install it on linux, I'm at a loss. I'm trying to use a .ftf file.
Does anyone have any pointers? Does this even have to be done with FlashTool? Could I use ADB? I would prefer installing Flashtool with Linux, if I have to use flashTool.