$ sudo apt-get update
$ sudo apt-get install linux-headers-4.2.0-27 

linux-headers-4.2.0-27 is installed in your system.

Make ensure the linux-headers-4.2.0-27 package were installed using the commands given below,

$ sudo dpkg-query -l | grep linux-headers-4.2.0-27 *

You will get with linux-headers-4.2.0-27 package name, version, architecture and description in a table

linux-headers-4.2.0-27 package basic information: