Upgrade Novell Identity Manager 3.6.1 to latest version

Hello friends,
Currently I have an environment of Novell Identity Manager 3.6.1 and need to make the upgrade to the latest version 4.0.1.
What requirements are needed to take into account to perform this update? What new functionality is incorporated into the new version of Novell Identity Manager 4.0.1.? I welcome your comments.

Thanks for the support friends.