Uninstall specific kernel version [closed]
As root, issue the following commands:
dpkg -l | grep linux-image
Find the kernel image you want to remove, which should be linux-image-3.8.0-27-generic (be sure it is).
Then
apt-get remove linux-image-3.8.0-27-generic
I don't think a GRUB update is needed, it should just disappear from the GRUB menu. If you get any errors with GRUB just issue, also as root, update-grub.