If you look at the source code. Every folder like commerceservices, centraloffice, all folders inside modules are separate projects. You need to import all or only the required projects in eclipse. While creating a new java project choose "create project from existing workspace" and use individual folders as a project. Since there is a lot of dependency among projects you need to clear all the errors by including the jars into the projects. After you are through with all the errors, you need to create a debug launcher like "remote application" in which you need to provide the IP and debug port of the machine where CO is running. By doing this, you will be able to debug application.
I have followed the same thing and i have created debug launcher like "remote java application" and given IP and debug port of the machine where CO is running. but when i am running project in debug as i am getting the following error-
'Launching integration' has encountered a problem.
failed to connect to remote VM.Connection refused.
Failed to connect to remote VM. Connection refused.
Connection refused: connect.
The port you are using must be the debug port. For weblogic, you need to modify setDomainEnv.cmd file and add a line at the very beginning "set debugFlag=true" and then restart the server. The default debug port in weblogic is 8453 and you should be using this in eclipse.
That means either you are not able to connect to that port or it has already connected and you are trying to re-connect. Open the debug perspective of eclipse to check whether you are already connected. If not, try telnet that port from your machine and check if its successful or not.