Hi there Ram,
You just need to exclude the current Hibernate dependencies/modules on your upgraded app jboss-deployment-assembly.xml descriptor, and manage the Legacy Hibernate dependencies directly in your app.
I recommend you to use the Windup tool as that one will scan your app and provide with the best paths for upgrade, with many options like keeping the current Hibernate, Upgrade Hibernate and removing Hibernate altogether, just in case you want to stick with plain old JDBC.
Let me know if I can help you with anything else!
JPA spec is backward compatible.
as long as you don't use any implementation specific code / configuration your application should run just fine with latest JPA spec / hibernate version.
in short, you don't need to do anything, especially do not bundle any hibernate dependencies with your deployment if you want to utilize that.