One way to handle this is by using the Export and Import tools by Bob Olde Hampsink. This will allow you to output the data to a CSV file, which you can hand off to the translator. Be wary though, if you have any complex fields (like custom field types), they may or may not export/import easily.
I would also strongly consider giving your translator temporary access to the CP. You could give them a temporary account with limited access, and point them straight to the pages which need translating. While your concerns over things like Matrix fields are valid, I'm not sure they outweigh the extra overhead of the exporting/importing process.
When used with Live Preview, giving access to the control panel also lets your translators see the strings they are translating used in the context of the site itself, which is useful when there might be multiple translations for a string.