IntelliJ IDEA to Eclipse migration; Tomcat

I have an application for Tomcat that has been developed in IntelliJ IDEA so far.
I need to go on with work in Eclipse.

Is there any way to export everything and import it in Eclipse?
I have a Tomcat plug-in for Eclipse.

How can I do this?

Regards

P.S.
I tried with File->Export and get the following message:
No modules can be exported. You cannot export modules which:
1.) have no content roots
2.) have multiple content roots
3.) have been already converted to Eclipse-compatible format