Default Importing feeds from Google Reader to Egress?

Hi!

Iíve been searching for a Rss Reader and am now testing Egress. Since I also use Google Reader, I would like to export those feeds and import them to Egress.
The problem is that when exporting from Google Reader the generated file is .XML, and Egress only imports .OPML files.

So, hereís the question:
How can I convert a .XML file to a .OPML file?
Or is there any other way of importing feeds from Google Reader to Egress?

Regards!