A hard drive is a hot-service component that can be replaced by a customer.
# cfgadm -al
This command lists dynamically reconfigurable hardware resources and shows their operational status. In this case, look for the status of the drive you plan to remove. This information is listed in the Occupant column.
Ap_id Type Receptacle Occupant Condition ... c2 scsi-sas connected configured unknown c2::w5000cca00a76d1f5,0 disk-path connected configured unknown c3 scsi-sas connected configured unknown c3::w5000cca00a772bd1,0 disk-path connected configured unknown c4 scsi-sas connected configured unknown c4::w5000cca00a59b0a9,0 disk-path connected configured unknown ...
You must unconfigure any drive whose status is listed as configured, as described in Step b.
# cfgadm -c unconfigure c2::w5000cca00a76d1f5,0
Replace c2::w5000cca00a76d1f5,0 with the drive name that applies to your situation.
Caution - The latch is not an ejector. Do not force the latch too far to the right. Doing so can damage the latch.
See Install a Hard Drive.