How to update Ubuntu 14.04

[Kernel, for ex: 14.04.1 to 14.04.5]

sudo uname -a ; ls -l /
sudo apt-cache search linux-image
sudo apt-cache search linux-header
sudo apt-get install linux-image-extra-4.4.0-124-generic
sudo apt-get install linux-headers-4.4.0-124-generic
sudo vim /boot/grub/menu.lst
---------------------------------------------------------------------------------------------------
default=0
timeout=3

title vmlinuz-4.4.0-124-generic
root (hd0,0)
kernel /boot/vmlinuz-4.4.0-124-generic root=/dev/xvda console=hvc0 ro
initrd /boot/initrd.img-4.4.0-124-generic

title vmlinuz-3.13.0-147-generic
root (hd0,0)
kernel /boot/vmlinuz-3.13.0-147-generic root=/dev/xvda console=hvc0 ro
initrd /boot/initrd.img-3.13.0-147-generic

---------------------------------------------------------------------------------------------------

sudo reboot
sudo uname -a ; ls -l /


[Distribution, for ex: 14.04.1 to 14.04.5]

sudo apt-get update
sudo apt-get dist-upgrade