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!
Customer surveys are for companies who didn't pay proper attention to begin with.
subject: how to install tomcat 5.5.26 on linux 64 bit machine