$ sudo apt-get update
$ sudo apt-get install kscreensaver-xsavers 

kscreensaver-xsavers is installed in your system.

Make ensure the kscreensaver-xsavers package were installed using the commands given below,

$ sudo dpkg-query -l | grep kscreensaver-xsavers *

You will get with kscreensaver-xsavers package name, version, architecture and description in a table

kscreensaver-xsavers package basic information: