UBUNTU // Handle old kernel mess

Automatic:

 dpkg-reconfigure unattended-upgrades
 vi /etc/apt/apt.conf.d/50unattended-upgrades

//Unattended-Upgrade::Remove-Unused-Dependencies “false”; —> //Unattended-Upgrade::Remove-Unused-Dependencies “true”;

By hand:

 apt install byobu
 purge-old-kernels

or

 apt autoremove --purge