HP Pro 3420 Maintenance & Service Manual page 54

6. If you need to remove the bezel from the optical drive, pull the right side of the bezel away from
the front of the drive, and then rotate it away to remove it. Make note of the tabs that hold the
bezel in place.
Figure 7-13
To install an optical drive, reverse the removal procedures.
46 Chapter 7 Removal and Replacement Procedures All-in One (AIO) Chassis
Removing the optical drive bracket