Dell XPS/Dimension XPS Gen 4 - Manual (Page 46)

2. Unsnap the top bracket hinge and pull the top of the drive door outward, away from the computer.
3. Lift the bottom bracket hinge away from the computer.
Replacing the Drive Door
To prevent damage to your computer, the drive door is designed to "break away" from the computer if it is opened too far. If the drive door detaches from the
computer without disassembling, perform the removal procedure in reverse.
If the drive door is open and it is opened too far, instead of breaking away from the computer in one piece, the drive door may disassemble into several
smaller pieces. If the drive door disassembles:
1. If necessary, reattach the door hinges to the door bracket. Ensure that the hinge tabs are away from the door bracket.