$ sudo apt-get update
$ sudo apt-get install khelpcenter4 

khelpcenter4 is installed in your system.

Make ensure the khelpcenter4 package were installed using the commands given below,

$ sudo dpkg-query -l | grep khelpcenter4 *

You will get with khelpcenter4 package name, version, architecture and description in a table

khelpcenter4 package basic information: