$ sudo apt-get update
$ sudo apt-get install libcegui-mk2-0.7.6 

libcegui-mk2-0.7.6 is installed in your system.

Make ensure the libcegui-mk2-0.7.6 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libcegui-mk2-0.7.6 *

You will get with libcegui-mk2-0.7.6 package name, version, architecture and description in a table

libcegui-mk2-0.7.6 package basic information: