Updating Ubuntu when /boot partition is almost full

Solution 1:

try

to check installed kernels first

dpkg --list | egrep -i --color 'linux-image|linux-headers' | wc -l

to delete older versions of kernel

sudo apt --purge <kernel> autoremove

or 

sudo apt-get --purge <kernel> autoremove

its mostly wise to keep older kernels to revert back to incase u face some problems