Hi, another 2 questions on entry level.
 

1. I have installed a software in usr/local/
How can I uninstall it? Just kill the diroectory and everything inside it? I don't think it is the correct way to do so.

2. I have a software, I un-tar it, and find a file called install-sh, how to execute it? Or I was looking for a wrong file to launch the installation.

Thanks a lot.

1) first, NO you will not delete /usr/local cause you'll bring down a lot with it, so the way you uninstall it depends on how you originally installed the program, if :::
you used rpm ->
rpm -e packagename
you used tarball ->
cd into the source directory (the extracted tarball)
and type the following
make uninstall
if your removed the source directory then you can look into the program called checkinstall ..
if there is a file called install-sh then more then likely all you will have to do is type one of the following (both are equivalent) ::
./install-sh
or...
sh install-sh
the typical steps for installing a tarball are ::
./configure
make
su -c "make install"
type root password
but if you are in the extracted folder and there is no configure script and the install-sh is one of the executable files in the folder then more then likely that script is set to install whatever you are trying to install.....everything is different, so that install-sh could be just to install some extra feature or something, i do not know as you didn't mention what you are trying to install or what the other executable files are, etc, etc...
but i think with the info given, you will be able to figure things out from there....

Actually I installed Mozilla 1.4, and I want to uninstall it now.
I untar the tar file, and run the installer, and it downloads files from the web, and then install.
Now I go to the installed directory "/usr/local/mozilla", there is nothing looks like an uninstall command.
What should I do?

well you obviosuly misunderstood what i said....i'll recap...
i said if you installed from source (tar.gz, tar.bz2) etc, etc..these are the files that you have to untar and uncompress...and when you do that to the compressed file you then get the source directory....which is the file you downloaded now extracted....
i am not reffering to the installation directory which is /usr/local/mozilla in your case, and no it does not have an uninstall command there...

Thanks.
I am downloading the check-install thing