the default rpm is spread all over the system
the tarbal is a "self contained " folder with almost everything needed
( the cent plugins are not in it )
BUT it should just auto find them all on it's own .
you just need to place it someplace
some leave it in there $HOME folder
I install it system wide
the normally used folder on rhel/cent/sl is "/opt"
kde3 and libreoffice and a few other things install there . It is as good a place as any .
then you need to tell the system ABOUT the new folder
that is where editing the /etc/profile file comes in
( and there are other ways to do that )
that is where this bit comes in
adding that location to the system $PATH
then when you run this command
that location WILL be there
then once the new firefox is working
you can then UNINSTALL the rpm
yum remove firefox
--- or the name might be ---
yum remove mozilla-firefox
the geko and media and flash plugins " SHOULD" be auto found
then a bit more work ( about 1 minutes worth of work )