Dell Precision 330 - Manual (Page 19)

1. Turn off the computer and peripherals, disconnect them from their electrical outlets, wait at least 5 seconds, and then remove the computer cover .
2. Rotate the power supply away from the system board.
3. Disconnect the DC power and interface cables from the back of the drive.
4. Remove the drive bracket from the chassis.
Remove the screw holding the drive bracket in the chassis. Lift the drive bracket up to disengage it from the latch on the externally accessible drive bay and the
three hooks on the front of the chassis (see the following figure).
Removing the Hard-Drive Bracket (Desktop Chassis)
5. Remove the four screws that secure the drive in the bracket (see the following figure).
6. Remove the old drive from the bracket
Removing a Hard Drive from the Bracket (Desktop Chassis)
Replacing a Hard Drive (Desktop Chassis)