Bertje

I am a new user. I want to cut out parts of an MP3 file. Putting and adjusting marks seems the best way of doing that. That functionality should be there, according to this help page. But the problem is I can't actually find it in the Edit menu. So what is going on? Is there some magical sequence? Or has it been removed, and the help not updated? I tried alternative selection by control-click, but that didn't work. Thanks.