The .episerverdata file is actually a zip library so you can rename the export file to .zip and unpack it. In the package you will see some files, the content items are in xml format e.g. in file epix.xml
Note however that working with the xml format directly is not "officially supported", what I mean with that is that the internal format of .episerverdata file and inside the xml files might change between versions.
I have a blog post where version 4 exportdata XML is handled. The XML format is different in 7.5 but you should get some benefit/inspiration on how to read the XML from taking a look:
Is it possible to export content items to XML format? I have tried using the export tool in EPiServer but the content is exported into .episerverdata format. I need to able to read the data in this file so it would be nice to have it XML format, is this possible?