your questions are a bit vague, but I'll try to answer anyway.
> What the files and tools are required to downloaded?
The same files you downloaded for 1.3.1, with the exception of the rmi
module which has been merged with the main openorb module. If you're
unsure, download everything that has 1.4.0 in the file name.
> What are the Customization we need to do?
Probably the same that you did for 1.3.1.
> What are the things needs to be taken care about the Java, tomcat and
> apache server?
Make sure that you have at least Java 1.4. Tomcat and apache I don't
know, that depends on your product.
> how to build this in the Clearcase.
This is related to your local/company build environment and dev process.
Ask your company's experts.
> what are installation and configuration information should be updated?
For openorb, it shouldn't be much. Check the WHATSNEW files of the
modules you are using for details.
> how much time it will take to complete the process of up versioning.
That completely depends on your product, how you use openorb, and
whether your test are manual or automatic. Could be anything from less
than a day (simple product where you control both ends of the remote
communication and have automated tests) to several weeks or months (full
test and release cycle for a complex life and death system that talks to
CORBA systems from other vendors).
Hope this helps,