posted 11 years ago
You shouldn't. Tomcat 5,5 is no longer supported.
If you insist on doing so anyway, go to the Tomcat legacy archives, download the binary ZIP file and unzip it. Just don't expect to find too many people answering your questions about it, since Tomcat 6 is what most people have been running for several years now and Tomcat 7 is the active release.
Welcome to the JavaRanch, by the way!
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.