Upgrading Tomcat server without harming the existing file

Job ID: 31129978

Budget: $10 – $30 USD

I'm looking for a person who know how to upgrade tomcat without affecting the existing files that are associated with the tomcat. (Meaning, if a certain app is running through tomcat and all of its data is in tomcat. I want the app to run as it is even after the tomcat has been upgraded).