When attempting to make this happen on 6.x I can’t find any place where the info can be imported. I have seen the import in 7.x, but that’s in the future right now.
To import reports in 6.0 you would go to the ‘custom’ section and then look towards the bottom of the page. You’ll see an ‘import’ button and a ‘new’ button. The import button will take you to a page where you can select the file you want to import while the new button will let you cut/paste the xml in or author the report by hand.