I had this same question to the QB back when I got my 15-91 (cabinet #41) and there were old patterns stuffed behind the drawers. So, if you pull the drawer out as far as you can andlook at the inside bottom of each drawer, you will see a small hole. Take something that will fit in the hole (awl or the like) and while pressing downward, pull the drawer out. There is a clip or something like that which inhibits the drawer from coming all the way out and by pressing downward, you will be pressing the clip down so it is not holding the drawer anymore. Someone here on the QB really helped me out with this so I am passing it along to you.