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
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) ::
the typical steps for installing a tarball are ::
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....