most likely the dvd they are currently in is a dual layer, unless you have a dual layer dvd r, you're going to want a program that will rip and compress and or give you the ability to remove streams dvd shrink is that program, get it here (it's free) and go here for a tutorial. Then just burn using nero 6 (regular retail version, oem version won't do) or some other program that will burn dvd's