First check the kernel version, so we won’t delete the kernel image in use:

1

uname -r

List installed kernels:

1

dpkg --list 'linux-image*' | grep ^ii

Delete unnecessary kernels (replace the VERSION with kernel that should be removed):

1

sudo apt-get remove linux-image-VERSION

After old kernels are removed, you can remove packages that are not used anymore:

1

sudo apt-get autoremove

Finally update grub kernel list:

1

sudo update-grub