$ sudo apt-get update
$ sudo apt-get install fglrx-pxpress 

fglrx-pxpress is installed in your system.

Make ensure the fglrx-pxpress package were installed using the commands given below,

$ sudo dpkg-query -l | grep fglrx-pxpress *

You will get with fglrx-pxpress package name, version, architecture and description in a table

fglrx-pxpress package basic information: