First, follow the instructions here:
http://www.urpmi.org/easyurpmi/ especiall the one at the bottom about removing your existing sources.
Urpmi is an automatic package installer. For example, if you wanted to install, say, Kwrite, you would open a console, use
su to become root and type in
urpmi kwrite, urpmi will go off to the web, find it and install it. If there is more than one package which matches your program name, it will list them and you can then narrow down what you need.