How to *update* a Fedora Core 3 component program?

[Bo Berglund <bo berglund telia com>]

I am new to Linux and Fedora Core 3 (installed yesterday)....

When I tried the web browser I found that it is FireFox 1.0 Preview
Release, so obviously I want to update it.
I can get the 1.0.4 installer all right and I can unzip it too, but
when I launch the install it looks like it is going to install a *new*
instance of the program and this is not what I want. I want a regular
software update, like when I install a new update of a program in
Windows. On that platform it updates the *existing* installation
instead of creating a new.

One of my reasons for this is that the FireFox is available on the
Applications menu in Fedora and I want to get the 1.0.4 launched from
there.

So these are my questions:
1) How can I *update* FireFox?
2) How can I in general uninstall programs in Fedora?
3) Should the installer not ask me to su before continuing?

Bo Berglund