I still don't understand why you need to create symlinks...
AFAIK, you install firefox in two ways:
1. By utilising the provided GUI installer, which is the default way.
2. By simply extracting all files into a local directory. (You need to search for it in the mozilla.org website since it is not easy to find this file...)
So, I assume that you use the first way.
1. Get firefox from mozilla.org.
2. Open a terminal, go to a temporary folder, say /tmp, and run the following command to extract the downloaded file.
$ tar xzvf /path/to/downloaded/firefox-1.0.7.installer.tar.gz
3. Go into the new folder.
$ cd firefox-installer
4. Become root and run the installer and follow the onscreen instructions. However, this doesn't always work due to a security feature in X window system which prevents root from running GUI program. So, first try as the following, if it doesn't work then read on.
In case this doesn't work straight, exit and return to a normal user and disable that security feature.
Now do the su -> firefox-installer thing again and hope that it works this time.
After finishing the installation, don't forget to turn the security feature back on as a normal user.
Hope this helps.