Java question

Does anyone know how to completely get rid of Java?  I am not very technical so a step by step explanation would be helpful, or alternatively, a link to a location that might help. Background: Although I uninstalled Java (via the add/remove programs) on my husband’s computer many  weeks ago, Firefox (which I downloaded last week because of the internet explorer problem) detected Java and warned that it needed to be updated and that Firefox blocked it.  So I downloaded the latest Java update and promptly deleted it thinking I could get rid of all the Java files that way.   But the Firefox warning was still there and a search of “Java” in the Windows search tool found a lot of Java files.  So I used a program called Java Ra to try to get rid of any remaining Java stuff and it did delete some Java files, but the Firefox warning remains, and the search tool also finds Java files. Among the files is  a Java Deployment Toolkit plug in which I have disabled in Firefox and Internet Explorer.  However, I read on the Oracle website page that explains the Java Deployment Toolkit that even if the plugin is disabled, it still works. I would like to eliminate anything Java. By the way, Norton indicated it eliminated a Trojan. Pidief on my husband’s computer on 9/9/2012.  I ran Norton Power Eraser and Malwarebytes and they are both clean and I checked all his programs and they are up to date.  Any suggestions/comments are appreciated.