Thank you for pointing on this.
I do exactly as it says, but I get a permission error for some reason. Despite reading following topics:
I do it like so:
sudo qvm-run --pass-io personal 'cat /home/user/Downloads/Sweet.tar.xz' > /usr/share/plasma/desktoptheme/sweet.tar.xz
and I get:
bash: /usr/share/plasma/desktoptheme/sweet.tar.xz: Permission denied
What am I doing wrong here, please?