There is no good way. There is no legal way either. Real has a 'closed codec'. You're not allowed to do anything with real media files other than play them. So even if you had real player installed you're stuck.

That being said, i have heard that there are some add-on utilties for the real alternative player that let you output the file into a different format, thereby allowing you to edit it. Just be forwarned that by doing so you'll be breaking the law.

I seem to recall that Real once offered an editor for real media files, but it was rather pricey and very limited. Does it still exist? I'm not curious enough to go look on their site.