Editing a .pgn

 Ok I grabbed the 7 .pgn files from the world championship. I wanted to use them in the board editor, but I do not know how to get into the .pgn file to copy the pgn string to paste it. Also my chessmaster 10th edition has an error when trying to load these games. I beleive I could edit the problem out, if I knew how to open them up.

  Can anyone explain how I get at the pgn string?

Open in notepad?

I play around with PGN's a lot of the time so I can tell you it's not complicated.  As Scottrf suggests, you can open any PGN (or FEN string) in any text editor.

In fact I've just tried it & the .pgn file downloads to your preferred download folder, then you can open it in Notepad & copy/paste into the Analysis/Game Editor - it works fine. Remember to select 'All file-types' instead of just '.txt' otherwise you won't see your dowloaded files !

If you want, you can collect a set of separate .pgn files into one text file & use them as you want - saves on space in your games folder.
Hint: You may need to disable 'Word-Wrap' in your text editor - it's given me a few problems before now !

Wikipedia is a really good source of information on this.

Edit:  Maybe not as easy as I thought - tried to play the first game ( 20120511.pgn ) in the game editor but only loads the first 24 moves !
Just realized that's where the game ended & what follows is just speculative variation.  But I'm not familiar with the 'z0' notation that follows that last move ?

Thank you!!  It was "all files" I needed to click.  Thanks to both of you. It wasn't showing because I had .txt left as the default.