root@angel:/# dpkg -l linux-* | awk '/^ii/{ print $2 }' | grep "\-2.6." | xargs sudo apt-get --dry-run remove
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
 linux-headers-generic : Depends: linux-headers-3.13.0-83-generic but it is not installed
E: Unmet dependencies. Try using -f.
root@angel:/# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            492M  4.0K  492M   1% /dev
tmpfs           101M  916K  100M   1% /run
/dev/sda1        11G  4.9G  5.5G  47% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
none            5.0M     0  5.0M   0% /run/lock
none            501M   76K  501M   1% /run/shm
none            100M   28K  100M   1% /run/user
/dev/sda8        47G  9.0G   36G  21% /home
/dev/sda5       4.5G  9.5M  4.2G   1% /usr/local
/dev/sda7       7.3G  464M  6.4G   7% /var