The upgrade needs a total of 97.6 M free space on disk'/ boot'. Please free at least an additional 62.1 M of disk space on '/boot'. Empty your trash and remove temporary packages of former installations using 'sudo apt-get clean'.
16.04 LTS installation on a 150G HDD This was a fresh install, /dev/sda1 'boot' was assigned 240972 blocks at the time of the installation. i.e. sudo apt-get clean didn't have anything to remove.
I have a 150 GB HDD in my PC. This is a desktop installation.
How do I fix the problem??
/boot
partition.sudo apt-get autoremove
did the trick for me, so your suggestion is valid.