Is there a way to export from K2 back to the Joomla core?

there is no default k2 option for this, but if you look thru the extensions here you can find k2csv import, that will rite to an excell sheet and you can use another joomla tool to import into articles

Thanks William, I will look through the extensions to see if there is one that will work. Have you used any extension to do this in particular?

havent tried it, always going foward...
you can also do it with phpmyadmin, but you will have to write your own scripts