Ok, get two of the 5.25 rails and what you have to do is screw the rails into the sides of the drive with the metal tabs facing forward (i.e. the area where you would put the cd/dvd in). Do this in such a way that the ends of the metal tabs line up with the front of the drive or are slightly behind it. After that, slide the drive with rails into the case from the FRONT, not from within. It should slide in and click into place when you've pushed it in far enough.