Ubuntu free up /boot to upgrade

Linux Kernel older images can take up all your /boot partition.  BUT there are times where the /boot is already at 100% hence you cannot perform any autoremove nor upgrade.

sudo apt-get -f autoremove

lsb_release -a;uname -a;dpkg -l|grep linux-image

Note the current used Linux kernel image so avoid it. Don't worry, if your current image has a dependency, it will warn you and will not remove them.

dpkg --purge <linux-image-not-needed> <linux-image-extra-not-needed>

sudo apt-get -f autoremove