How to remove a directory which has other directories in it?

[Varuna Seneviratna]

I Downloaded tomcat6 core and uncompressed using the tar utility and
the result was apache-tomcat-6.0.32.Now I want to remove it.

When going through the Graphical mode to the Downloads directory and
try to delete it it says permission denied.

When trying to use the rmdir command as root the message is that the
directory is not empty.How to remove a directory which has many files
in it from the command line or through the graphical mode to which
normally the message you get is permission denied ?