Old thread, but just wanted to tell everyone about the wonders of Ultimate Vocal Remover 5.
I had tried to remove unwanted talking with iZotope as nulldogmas explained above, but I could never get good results. However, this free program has worked very well for me almost every time I have used it. It hasn't been able to remove some very quiet talking, but it has done a great job removing all the loud talking, and it usually can remove "woo-hoo's" as well.
I have cut out sections with talking, run them through the program, which splits it into instrumental and vocal tracks, then pasted the instrumental track back into the original recording. Listening to the vocal track is also interesting, you can hear just what the douchebags were talking with their friends about!
The only time I found it didn't work well was when there was talking over the very beginning of a song, when the drummer did a tapping count in (four taps of something in a row, not sure exactly what he was tapping). Unfortunately the tapping was put into the vocal track instead of the instrumental track. And of course you can't really use it for sections where people talk while there is singing onstage, or it will take out the singing as well. Maybe someday that can be perfected as well.
https://ultimatevocalremover.com/