http://texturizer.net/firefox/download.html#install - didn't make any sense to me...
OK, from that page I can see you have the option to download one of two binary distributions, for use with GTK or for use with XFT and GTK2, or you can download source.
If you want to use the source, you will probably have to have the development versions of GTK and so on installed first. You probably don't have these. It will be a world of pain for you :-)
On the other hand, you probably do have GTK run-time libraries available, so the "binary using GTK" option looks best for you. If you unpack that, as Ed says, you'll find a "Firefox" script in there.
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/firefox-i686-pc-linux-gnu.tar.gz
On the whole, I'd advise the above link :-) That'll be quickest.
-jim
