The two methods use "rpm" files or "tar" files (compressed and shown as "gz" or "bz2").
The rpms can be found here (two mirrors are given in case one is slow or down):
The following link explains how to use the GUI to install them. This can all be done via the CLI, but I have never tried it. I have always been successful by first using YaST to delete the old rpm, and have never done it any other way for installs of this type. If you need to install the "translations" rpm, which is optional if you don't need foreign language support,, then install that one first, and then the main firefox rpm as described in the link below. This may prevent a possible dependency problem.
Using the "tar" file is a very easy way to install firefox, since all the files end up in one directory, which is not the case for all tarballs. I believe that there is a CLI command to "look inside" a tarball to see where the files will be extracted to before you install it, and you should check the man page, and google, for more info on that. The GUI programs mentioned below will also show you that info before you actually extract/install. As a regular user, create a directory/folder in your "home" directory where your "dot" files and personal files are, and give it a name, say (ffox). Now download the Linux tarball from Mozilla at: http://www.mozilla.com/
, move the file into the directory that you created, and use "Ark", "File-Roller", "Karchiver", or the CLI to extract/install all of the files from the tarball. Once that is done, you only have to set your links/shortcuts to point to the start script, for example (/home/bill/ffox/firefox/firefox). If you want to uninstall/re-install, all you have to do is delete the "firefox" directory that is inside the "ffox" directory, then extract the tarball again.
Good luck !