You only have to copy the jar file, no change in the code is required.
Do you mean copy the jar files from the 4.03 endorsed dir to 4.0.1sp1 endorsed dir? If so, I tried that, but that doesn't work because jboss is using these jar files on startup. When I copied these jars to this directory it will not start up. Or do you mean copy the jar files from the 4.0.3 endorsed dir to my application directory? I am not for sure what version of xerces that 4.0.1 is using, but I would think it is using a different version to what I need.