This link tells you how to do the opposite of what you want, but it may be useful anyway (maybe you can reverse the procedure)
http://uscfsales.wordpress.com/2011/08/12/importing-pgn-games-into-the-fritzrybka-interface/
Using search engines is usually faster (and often more accurate) to get answers http://www.cln.org/searching_faqs.html/
I'm trying to get my chessbase games on a tablet. The tablet app needs games in .pgn All of my games on fritz 13 are on .cbv and apparently can be changed to .pgn.
Any idea on how to do that within fritz 13. thx.