You can download with wget from a terminal (the files will be downloaded in the current directory) :
Log on with your normal user name.
First, download installation instructions:
From a terminal you can read the readme file with:
cat readme0328.txt | less
Find which XFree86 version is installed on your system (probably 4.3):
download the driver for XFree86 4.3:
(if XFree86 version is 4.2 you should use instead : wget http://www2.ati.com/drivers/linux/fglrx-glc22-4.2.0-3.2.8.i586.rpm)
then install the rpm as root with rpm -ivh or urpmi.