Vob files to DVD

Hey,

I have like 7 karaokes dvds, and the thing is I want one song from each dvd and burn it onto a new karaoke dvd. I’ve extract the VOB and IFO from the dvd with dvdcrypter (using IFO mode) but after that I am hopeless… I dont know what to do. I read the tutorial with Dvdshrink but im all confused…