In case of mozilla you do not have to do anything on your side
Just go to a site (like
www.bbc.com/news) that has Java Applets in it.
Mozilla will complain about the plugin.Say yes to the dialog that apperas.Mozilla will take you to a page where you can clikc the button to download and install the Java Plugin. You do nto have to do anything:everything happens automatically!
Hope that help...