Don't you import it when you create a new virtual machine? You create a new one and then when it asks for the image or install CD, you'd choose to import one. Or maybe the new version has a file > import option. You can also try getting the importer off an old version of the software here:http://kb.parallels.com/en/5802
Don't install the software but see if you can extract the transporter from say the version 4 dmg.